PLENARY - University of Missouri–St....
Transcript of PLENARY - University of Missouri–St....
TABLE OF CONTENTS PROGRAM……………………………………………………………………………………..5
PLENARY
STEM CELL AND NUCLEAR BIOPHYSICS - NANOMECHANICAL ASPECTS OF DIFFERENTIATION................... P1
BIOMEDICAL APPLICATIONS OF SCANNING ION CONDUCTANCE MICROSCOPY............................................. P2
NANOMEDICINE: NEW APPROACHES TO OLD PROBLEMS ............................................................................... P3
ENGINEERING CARBON NANOTUBE ARCHITECTURES...................................................................................... P4
CELLULAR SENSING OF FORCE AND GEOMETRY THROUGH FORCE-DEPENDENT UNFOLDING AND
ONCOGENE PHOSPHORYLATION........................................................................................................................ P5
INVITED
BIOLOGICALLY-INSPIRED ENGINEERING AND MEMS FOR REALIZATION OF NANOMEDICINE ...................... I1
MULTI-FUNCTIONAL NANOSYSTEMS FOR TUMOR-TARGETED DRUG AND GENE DELIVERY ......................... I2
A NOVEL PCR BASED DNA MICRO-ANALYZER.................................................................................................. I3
SECOND HARMONIC GENERATION IN COPPER NANOPARTICLES ..................................................................... I4
MULTIMODAL CERAMIC NANOVECTOR ............................................................................................................. I5
INTEGRATED SYSTEMS FOR MANUFACTURING AT THE NANOSCALE .............................................................. I6
APPLICATION OF INNOVATIVE FLUIDICS APPROACHES FOR AIR AND LIQUID BASED BIOLOGICAL POINT
DETECTORS.......................................................................................................................................................... I7
SYNTHESIS OF NANOSTRUCTURED SPINTRONIC MATERIALS USING PULSED LASER DEPOSITION................. I8
SELF-ASSEMBLING OF AU AND AG NANOPARTICLES USING HYDROGEN BONDING ....................................... I9
NANOSCIENCE AND NANOTECHNOLOGY RESEARCH AT THE WILLIAM L. CLAY CENTER FOR MOLECULAR
ELECTRONICS AT THE UNIVERSITY OF MISSOURI-ST. LOUIS........................................................................ I10
DENSITY FUNCTIONAL THEORY: FROM CONVENTIONAL BULK TO NANOPOROUS MATERIALS .................. I11
CONTRAST-ENHANCED RADIOTHERAPY OF CANCER ..................................................................................... I12
NANOMEDICINE IMPROVES DRUG SAFETY AND EFFICACY............................................................................. I13
CHEMICALLY RESPONSIVE NANOREACTOR MATERIALS FOR BIOLOGY AND MEDICINE ............................. I14
FIRST-PRINCIPLES STUDY OF BORON NANOSTRUCTURES: SHEETS AND NANOTUBES.................................. I15
FUNCTIONAL DENDRITIC MATERIALS AND ORGANIC-INORGANIC HYBRID MATERIALS ............................. I16
2
GOLD NANOPARTICLE BASED FRET ASSSAY FOR DETECTION OF DNA HYBRIDIZATION AND CLEAVAGE.. I17
COMBUSTION SYNTHESIS OF ULTRA-HIGH SURFACE AREA METAL FOAMS................................................. I18
DEVELOPMENT OF POROUS GOLD AS A SUPPORT FOR BIOMOLECULE IMMOBILIZATION AND ITERATIVE
SYNTHESIS.......................................................................................................................................................... I19
APPLICATIONS OF MINIATURIZATION SCIENCE IN CELL RESEARCH ............................................................ I20
POSTERS-LIFE SCIENCES
FREE ENERGY PROFILE OF SINGLE FILE WATER MOLECULES IN CARBON NANOTUBES..............................L1
A SIMPLE AND FAST CT SIMULATION PROGRAM FOR ESTIMATION OF CONTRAST FROM NANOMATERIALS.
.............................................................................................................................................................................L2
CONTROLLED STIMULATION OF QUANTAL CATECHOLAMINE RELEASE FROM CHROMAFFIN CELLS USING
PHOTOLYSIS OF CAGED CA2+ ON TRANSPARENT INDIUM-TIN-OXIDE MICROCHIP ELECTRODES................L4
A GLUCOSE BIOSENSOR ENCAPSULATED IN ERYTHROCYTES .........................................................................L5
RECONSTRUCTION OF FREE ENERGY PROFILES FROM FAST NONEQUILIBRIUM PROCESSES .......................L6
THEORETICAL PREDICTION OF OPTICAL AND SPECTRAL PROPERTIES OF PIGMENT-PROTEIN COMPLEXES
.............................................................................................................................................................................L7
LONGITUDINAL NANOSTRUCTURE STUDY OF THE ISLET IN THE NOVEL HIP RAT MODEL OF TYPE 2
DIABETES MELLITUS..........................................................................................................................................L8
NANOENGINEERING OF AMINOSUGAR FUNCTIONALIZED GOLD NANOPARTICLES FOR SURFACE TARGETING
OF CANCER CELLS .............................................................................................................................................L9
SYNTHESIS AND IN-VITRO STUDIES OF GLYCOPROTEIN LABELED GOLD NANOCHAIN...............................L10
SIZE CONTROLLED SYNTHESIS OF MAGHEMITE NANOPARTICLES FOR BIOMEDICAL APPLICATIONS .......L11
BIOSENSOR DESIGN AND FABRICATION USING GOLD NANOPARTICLES .......................................................L12
DETECTION OF HIV-1VIRAL ENVELOPE SURFACE PROTEINS USING QUANTUM DOTS AND FÖRSTER
RESONANCE ENERGY TRANSFER (FRET) IN LIQUID CORE WAVEGUIDES.....................................................L13
PRODUCTION OF GOLD 198/199 NANOPARTICLES FOR POTENTIAL USE IN DIAGNOSIS AND TREATMENT OF
CANCER.............................................................................................................................................................L14
CELLULAR SENSING OF FORCE AND GEOMETRY THROUGH FORCE-DEPENDENT UNFOLDING AND
ONCOGENE PHOSPHORYLATION......................................................................................................................L15
SYNTHESIS AND APPLICATION OF NANOSTRUCTURED MATERIALS AND BIOMEDICAL MATERIALS ..........L16
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SCANNING ION CONDUCTANCE MICROSCOPY REVEALS CLUSTERED PUNCTATE DEPRESSIONS AND VALLEYS
IN THE PLASMA MEMBRANE DURING STIMULATION OF EXOCYTOSIS FROM CHROMAFFIN CELLS...........L17
DEVELOPMENT OF AN OPTICAL NANOBIOSENSOR FOR DETECTION OF PRRS.............................................L18
APPLICATION OF ATOMIC FORCE MICROSCOPY AND FLUORESCENT MICROSCOPY IN STUDY OF THE
MECHANOTRANSDUCTION OF VASCULAR SMOOTH MUSCLE CELLS ............................................................L19
IMMOBILIZATION OF PEPTIDES ON QUANTUM DOTS FOR THE DEVELOPMENT OF A PROTEASE BIOSENSOR
...........................................................................................................................................................................L20
POSTERS-MATERIAL SCIENCES
COMPACT POWER GENERATION USING METASTABLE INTERMOLECULAR COMPOSITE (MIC) MATERIAL.M1
RAMAN SPECTROSCOPIC STUDIES OF SEMI-CRYSTALLINE POLYFLUORENE UPON THERMAL CYCLING....M2
GAS STORAGE CAPABILITIES AND STRUCTURE OF NANOPOROUS CARBON..................................................M3
SPECTROSCOPIC STUDIES OF NANOPARTICLES AND NANOSTRUCTURED SURFACES ....................................M4
MOLECULAR DYNAMICS SIMULATION OF THE SIZE EFFECT OF CARBON NANOTUBES ON THE MATERIAL
PROPERTY OF A LIPID BILAYER ......................................................................................................................M5
DIELECTROPHORETIC FABRICATION OF 1D-NANOMATERIAL-BASED DEVICES............................................M6
GIANT MAGNETORESISTANCE EFFECT IN ORGANIC-INORGANIC HETERO-STRUCTURE SPINTRONIC DEVICES
............................................................................................................................................................................M7
MOLECULAR DYNAMICS SIMULATION OF THE SIZE EFFECT OF CARBON NANOTUBES ON THE MATERIAL
PROPERTY OF A LIPID BILAYER ......................................................................................................................M8
HIGHLY CONDUCTIVE AND TRANSPARENT ZNALO THIN FILM FOR ORGANIC LIGHT EMITTING DIODES ..M9
MICROWAVE PLASMA-ASSISTED CHEMICAL VAPOR DEPOSITION REACTOR: INSTRUMENTATION AND
IMPLEMENTATION FOR CARBON-BASED MATERIALS FOR ELECTRONIC DEVICES AND BIOSENSING
APPLICATIONS* ...............................................................................................................................................M10
NANOSCALE SURFACE CHARACTERIZATION WITH NONLINEAR PARAMETER IDENTIFICATION ................M11
SIZE CONTROLLED SYNTHESIS OF MAGHEMITE NANOPARTICLES FOR BIOMEDICAL APPLICATIONS ......M12
NOVEL SIO2 COATINGS FROM BIOMINETICS\ ................................................................................................M13
PULSED POWER GENERATION USING THE RELEASED HEAT OF NANO-ENGINEERED THERMITES............M14
LIGHT WAVEGUIDES WITH AN AQUEOUS CORE AND AN ULTRA LOW REFRACTIVE INDEX NANOPOROUS
SILICA CLADDING............................................................................................................................................M15
MIC COMBUSTION WAVEFRONT VELOCITY IN ELASTOMERIC MICROCHANNELS ......................................M16
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GROWTH AND CHARACTERIZATION OF NANOSIZE CO- DOPED ZNO DILUTE MAGNETIC SEMICONDUCTORS
..........................................................................................................................................................................M17
SPECTROSCOPIC ELLIPSOMETRY ANALYSIS OF NANOPOROUS LOW DIELECTRIC CONSTANT FILMS
PROCESSED VIA SUPERCRITICAL CO2 FOR NEXT-GENERATION MICROELECTRONIC DEVICES.................M18
NANOCOMPOSITE DIELECTRICS FOR QUANTUM DEVICES............................................................................M19
WRAP-AROUND-GATE SILICON NANOWIRE NMOS INVERTER WITH LOW POWER CONSUMPTION AND
ENHANCED SPEED............................................................................................................................................M20
SELF ASSEMBLY OF OXIDE NANO-STRUCTURES USING PULSED LASER DEPOSITION.................................M22
COPPER CHLORIDE BASED SOL-GEL SYNTHESIS OF COPPER OXIDE FOR USE IN NANO-ENERGETIC
MATERIALS......................................................................................................................................................M23
SYNTHESIS AND CHARACTERIZATION OF COPPER OXIDE BASED NANOENERGETIC COMPOSITES ...........M24
FIELD-EFFECT TRANSISTORS BASED ON SINGLE NANOWIRES OF CONDUCTING POLYMERS ....................M25
LATTICE FRINGE SIGNATURES OF EPITAXY ON NANOTUBES.......................................................................M26
PLASMA NANOCOATED DIAMOND NANOPARTICLES FOR HEAT TRANSFER NANOFLUIDS ..........................M27
ELECTRICAL CHARACTERIZATION OF POLYFLUORENE-BASED METAL-INSULATOR-SEMICONDUCTOR
DIODES .............................................................................................................................................................M28
PORE STRUCTURE IN ACTIVATED CARBON WITH APPLICATIONS TO METHANE STORAGE .......................M29
COHERENCE EFFECTS IN ELECTRON DIFFRACTION FROM PRESOLAR GRAPHENES...................................M30
PULSED POWER GENERATION USING THE RELEASED HEAT OF NANO-ENGINEERED THERMITES............M32
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PROGRAM October 6 (Friday)
Life Sciences Center 10:30-11:30 AM Registration
11:30-12:45 PM Lunch
Schlundt Hall Room 103
12:45-01:00 PM Introductory Remarks: William Crist, Dean, School of Medicine, UMC
01:00-01:45 PM Plenary Talk 1: Dennis Discher, University of Pennsylvania,
“Stem cell and Nuclear biophysics - Nanomechanical aspects of differentiation”
01:45-02:15 PM
Plenary Talk 2: Linda Molnar, NIH/NCI
"Transforming Technologies for Cancer Diagnosis, Prevention, and Treatment:
Opportunities in Cancer Nanotechnology”
02:15-02:30 PM Coffee break
Concurrent Session: Life Sciences and Material Sciences Research
Session 1: Life Sciences (Physics
Building Room 126)
Session 2: Material Sciences (Physics Building
Room 120)
Session Chair: Sherman Fan Session Chair: Suchi Guha
02:30-03:00 PM Mansoor M. Amiji, Northwestern
University J. Liu, University of Missouri - St. Louis
03:00-03:30 PM Hayat Onyuksel, University of Illinois K. Kimura, University of Hyogo, Japan
03:30-04:00 PM Paresh C. Ray, Jackson State
University
Puspendu K. Das, Indian Institute of Sciences,
India
04:00-04:30 PM Svetlana Tatic Lucic, Lehigh
University
Zhonghua Peng, University of Missouri - Kansas
City
04:30-05:30 PM POSTER SESSION- LIFE SCIENCES CENTER
Dinner and Lecture
(Stotler Lounge, Memorial Union)
06:30-07:30 PM Drinks/Appetizer
07:30-10:30 PM Plenar Talk: Gregory Lanza, Washington Univerity, St. Louis “Nanomedicine:
“New Approaches to Old Problems”
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October 7 (Saturday)
Life Sciences Center - Monsanto Auditorium
07:00-08:00 AM Continental Breakfast
08:00-08:45 AM
Plenary Talk 1: Michael Sheetz, Columbia University
“Cellular Sensing of Force and Geometry through Force-dependent Unfolding
and Oncogene Phosphorylation”
08:45-09:30 AM Plenary Talk 2: Yuri Korchev, Imperial College, London
“Biomedical Applications of Scanning Ion Conductance Microscopy”
09:30-09:45 AM Coffee break
Concurrent Session: Life Sciences and Material Sciences Research
Session 1: Life Sciences (Physics Building
Room 126)
Session 2: Material Sciences (Physics
Building Room 120)
Session Chair: John Viator Session Chair: Sheila Grant
09:45-10:15 AM Kevin Morris, Sirius Medicine, LLC Julie Medvedeva, University of Missouri
- Rolla
10:15-10:45 AM Demir Akin, Purdue University Ravindra Pandey, Michigan Tech Univ.
10:45-11:15 AM Agnes Ostafin, University of Utah Sandwip Dey, Arizona State University
11:15-12:00 PM POSTER SESSION- LIFE SCIENCES CENTER
Life Sciences Center 12:00-01:00 PM Lunch
01:00-01:45 PM Plenary Talk: Pulickel M. Ajayan, Rennselaer Polytechnic Institute
“Engineering Carbon Nanotube Architectures”
01:45-02:00 PM Break
Concurrent Session: Life Sciences and Material Sciences Research
Session 1: Life Sciences (LSC-Monsanto
Auditorium)
Session 2: Material Sciences (Physics
Building Room 120)
Session Chair: Evan Boote Session Chair: Hao Li
02:00-02:30 PM Alex Freeman, Midwest Research Institute Kartik Ghosh, Missouri State University
02:30-03:00 PM Shantanu Bhattacharya, Purdue University Placid M. Ferreira, University of
Illinois
03:00-03:30 PM Keith Stine, Univ. of Missouri - St. Louis Steve Son, Purdue University
03:30-03:45 PM Break
03:45-04:00 PM MO-NANOALLIANCE BUSINESS MEETING
04:00-04:30 PM POSTER AWARDS
7
PLENARY
P 1
STEM CELL AND NUCLEAR BIOPHYSICS - NANOMECHANICAL
ASPECTS OF DIFFERENTIATION
Dennis E. Discher
University of Pennsylvania, Philadelphia, PA 19104-6315 Email: [email protected]
Microenvironments appear important in stem cell lineage specification but can be
difficult to adequately characterize or control with soft tissues. Naive mesenchymal stem
cells (MSCs) are shown to specify lineage and commit to phenotypes with extreme
sensitivity to tissue level elasticity. Soft matrices that mimic brain are neurogenic, stiffer
matrices that mimic muscle are myogenic, and comparatively rigid matrices that mimic
collagenous bone prove osteogenic. Inhibition of nonmuscle myosin II blocks all elasticity
directed lineage specification–without strongly perturbing many other aspects of cell function
and shape. The nano/micro length scale of "microenvironment" will be described together
with the relation to nano-remodeling within the nucleus. The results have significant
implications for understanding physical effects of the in vivo microenvironment and also for
therapeutic uses of stem cells.
P 2
BIOMEDICAL APPLICATIONS OF SCANNING ION CONDUCTANCE
MICROSCOPY
Yuri Korchev
Imperial College London, London Centre for Nanotechnology, Division of Medicine, BN5
Commonwealth Building, Hammersmith Campus, Du Cane Road London W12 0NN, UK
Research in nanotechnology began with applications outside of biomedicine and is
based on discoveries in physics and chemistry. This is because it is essential to understand
the physical and chemical properties of molecules or complexes of molecules in order to
control them. The same holds true for the molecules and structures inside living tissues. We
need more detail on the physical properties of intracellular structures, and how biology's
molecular machines are built. This basis, in turn, will enable drug development and therapy.
This approach ultimately requires the development of novel biophysical methods. For
example, image living and functioning cells on the nanoscale and make quantitative
measurements down to the level of individual molecules and their complexes. We have
recently pioneered the development of an array of new and powerful biophysical tools based
on Scanning Ion Conductance Microscopy that allow quantitative measurements and non-
invasive functional imaging of single protein molecules in living cells. Scanning ion
conductance microscopy and a battery of associated innovative methods are unique among
current imaging techniques, not only in spatial resolution of living and functioning cells, but
also in the rich combination of imaging with other functional and dynamical interrogation
methods. These methods, crucially, will facilitate the study of integrated nano-behaviour in
living cells in health and disease.
P 3
NANOMEDICINE: NEW APPROACHES TO OLD PROBLEMS
Gregory Lanza
Washington University Medical School, CTRAIN Group, St. Louis, MO 63110 Email: [email protected]
Nanomedicine combines the myriad advances in a broad range of disciplines with
developments in nanotechnology to offer new opportunities for medical diagnosis and
therapy. The application of these emerging technologies is not confined to incremental
improvement in current medical strategies, but includes the detection and treatment of disease
earlier than currently feasible. In some foreseeable examples, the natural history of disease
could be greatly slowed and possibly disrupted.
We must recognize that nanotechnology is not the solution to all biomedical problems
that beset us today, but nanoparticles have physical properties that provide unique advantages
over the drugs and agents in our pharmacopeia today. Specifically, nanoparticles have
extraordinary surface-to-volume ratios that accommodate high surface payloads of drugs,
metals, or homing ligands and concomitantly foster prolonged circulatory persistence.
Differences in the composition and relative size of these agents significantly guides potential
use, such that a variety of “nanoceuticals” are emerging to address different problems.
One illustrative example is a multi-modal site-targeted contrast agent based on
perfluorocarbon emulsions, which has been demonstrated to provide sensitive and specific
imaging of molecular epitopes and local therapy in multiple animal models. This novel
platform has been used to detect angiogenesis, fibrin, tissue factor and collagen III and to
locally deliver therapeutic agents through a unique mechanism we term “contact-facilitated
drug delivery”. Clinical trials are expected to begin next year. Biomedical nanotechnology
is not a distant goal, the first generation agents are in the clinical pipeline today. Over the
next decade, molecular imaging, in conjunction with rational targeted therapies, will likely
impact all of us. For patients, it will represent longer and better quality of life. For
communities and states, it will fuel new business development, create jobs, and strengthen
local economies. Clearly, everyone has a vested interest in the success of these emerging
technologies.
P 4
ENGINEERING CARBON NANOTUBE ARCHITECTURES
Pulickel M. Ajayan
Department of Materials Science and Engineering, Rensselaer Polytechnic Institute
Troy, New York 12180-3590, U.S.A. Email: [email protected]
Carbon nanotubes are fascinating materials from the point of view of structure, form,
growth and properties. The biggest challenge however is to assemble nanotubes into various
architectures useful for specific applications. The talk will focus on the recent developments
in our laboratory on the fabrication of carbon nanotube based architectures tailored for
various applications. Various organized architectures of multiwalled and singlewalled carbon
nanotubes can be fabricated using relatively simple vapor deposition techniques. The work in
attaining control on the directed assembly of nanotubes on various platforms will be
highlighted. Our efforts on the strategies of growth and manipulation of nanotube-based
structures and in controllably fabricating hierarchically branched nanotube and nanotube-
hybrid structures will be discussed. We have pursued several novel applications for these
structures, for example, as nanostructured electrodes for sensors, electrical interconnects,
unique filters for separation technologies, thermal management systems, multifunctional
brushes, and polymer infiltrated thin film and bulk composites. A perspective of the field
based on the work done by the author over a period of more than decade will be presented
here with highlights from recent work and thoughts on future implications of the field.
P 5
CELLULAR SENSING OF FORCE AND GEOMETRY THROUGH
FORCE-DEPENDENT UNFOLDING AND ONCOGENE
PHOSPHORYLATION.
Michael P. Sheetz Department of Biological Sciences, Columbia University, New York, NY 10027
Email: [email protected]
The shape and behavior of mammalian cells is defined by an interplay between extracellular signals (physical and chemical) and the cellular responses. In particular, external molecular-level geometry and forces have major effects on cell behavior (Vogel and Sheetz, Nature Rev. Mol. Cell Biol. 7:265, 2006). A prominent example is the rigidity response since transformed cells can often grow on soft agar whereas normal cells require rigid surfaces to grow, i.e. oncogenes are involved in defining cell mechanics (reviewed in Giannone and Sheetz, Trends Cell Biol., 16:213, 2006). Thus, a critical component for cancer is the ability to override the requirement for force production and rigidity response. For most mammalian cells there are relatively few types of motility that are evident from quantitative analyses of rapidly spreading fibroblasts (Dubin-Thaler et al., Biophys. J. 86:1794-1806, 2004). One motile phase that we have studied extensively involves periodic contractions (24 s period) in local regions of the leading edge of the cell (Giannone et al., Cell, 116:431-443, 2004). The periodic signal is carried radially from the cell edge toward the center and is part of a general mechanism for rigidity-directed movement and pathfinding. Another motile phase involves the movement of individual collagen fibers in a hand-over-hand fashion (Meshel et al., Nature Cell Biol. 7:157-164, 2005) where the geometry of the fiber is being sensed. Rigidity and geometry responses in these systems are dependent upon the cytoskeleton and force-dependent tyrosine phosphorylation through oncogenes (Sawada and Sheetz, J Cell Biol. 156:609-15, 2002; Tamada et al., Developmental Cell, 7:706-718, 2004) that appears to involve unfolding of cytoplasmic kinase substrates, particularly p130Cas (Sawada et al. ). Recent studies indicate that the cell rigidity response requires RPTPα and occurs preferentially at the leading edges of moving cells through forces of 10-20 pN generated by displacements of 50-100 nm (Jiang et al., Biophys J. 90:1804, 2006). The mechanism of rigidity response involves recruitment of Fyn kinase in a palmitoylation-dependent process and the phosphorylation of p130Cas at the leading edge (Kostic and Sheetz, Mol Biol Cell, 17:2684, 2006). A displacement mechanism for the rigidity response is postulated. We will discuss how cells organize motility tools in motile phases (Döbereiner et al., Phys. Rev. Letters. 93:108105-1-4, 2004) in a dialogue with the environment to define cell morphology and behavior over time.
P 6
INVITED
I 1
BIOLOGICALLY-INSPIRED ENGINEERING AND MEMS FOR
REALIZATION OF NANOMEDICINE
Demir Akin
Purdue University, West Lafayette, IN 47907-2016
Recent developments in the nanotechnology and microelectronics fabrication areas
are opening new venues in diagnostic and therapeutic medicine, which are collectively
named Nanomedicine. To realize the goals of nanomedicine, concepts and tools from
BioMEMS and biomimetic engineering are used as a bridge between the nano and macro
world. Towards these goals, on the diagnostics side, we are working on the development and
characterization of micron to nanometer scale devices to isolate, fractionate, concentrate, and
detect infectious/biothreat agents and molecules of biomedical interest from fluids and air.
On the therapeutic side, we are working on the design of functionally engineered molecules
and the use of facultative intracellular microorganisms to target and deliver stimuli
responsive intelligent drug molecules into cancer cells. Nature has been the greatest
inspiration for our work. In this respect, I will give some examples and provide some future
goals for our research in the area of molecular engineering and nanomedicine.
I 2
MULTI-FUNCTIONAL NANOSYSTEMS FOR TUMOR-TARGETED
DRUG AND GENE DELIVERY
Mansoor M. Amiji
Professor and Associate Department Chair , Co-Director, Nanomedicine Education and Research Consortium (NERC)
Northeastern University, Boston, MA Email: [email protected]
Nanotechnology is expected to have a revolutionary impact on cancer diagnosis and therapy. In cancer therapy, targeting and localized delivery are the key challenges. To wage an effective war against cancer, we have to have the ability to selectively attack the cancer cells, while saving the normal tissue from excessive burdens of drug toxicity. Furthermore, newer generation of molecular therapies, such as gene therapy and siRNA, will require intracellular delivery strategies for effective outcomes. In this presentation, I will discuss the different nanotechnology platforms that we have developed over the last ten years for targeted drug and gene delivery to the tumor mass. Using biodegradable polymers, we have formulated nanocarriers for hydrophobic anticancer drugs such as paclitaxel and tamoxifen. These nanocarriers can be tuned to release their content either by slow diffusion or upon pH-responsive trigger. Recently, we have used these nanocarriers for combination drug delivery to overcome multidrug resistance in cancer. Gelatin-based nanocarriers are developed for tumor-targeted gene delivery. Using plasmid DNA encoding for soluble Flt-1 (VEGF-R1) receptor, we show enhanced transfection and therapeutic efficacy in human breast cancer xenograft model. Nanomemulsion are heterogenous liquid system comprising of oil droplets in the nanometer length scale surrounded by water. Using oils rich in polyunsaturated fatty acids (e.g., �-linolenic acid), we have developed nanoemulsions that can facilitate drug delivery across different biological barriers, such as the blood-brain barrier. In addition, these nanoemulsions can be used for combination magnetic resonance imaging (MRI) and drug delivery for image-guided cancer therapy. Lastly, we work on metal nanoparticles, primarily gold and iron oxide-gold core-shell nanosystems. Multifunctional gold nanoparticles allow for simultaneous imaging and gene delivery in cells. Superparamagnetic iron oxide-gold core-shell nanoparticles are used for magnetic cell separation, MRI contrast enhancement, and hyperthermia.
I 3
A NOVEL PCR BASED DNA MICRO-ANALYZER
Shantanu Bhattacharya
Birck Nanotechnology Center, Purdue University Email: [email protected]
A micro-fluidic assay to quickly analyze microscopic samples of DNA is being developed for field applications. It consists of a micro-PCR chamber, micropumps, and micro-heaters. Additional components of the device include gel electrophoresis micro-channels and solid core waveguide fluorescence collectors. We have investigated the surface dynamics of a novel polymer surface coating to achieve amplification of template with pico-gram level concentration. Confirmation of surface behavior with ATR FTIR has revealed the temporal transition of the coating surface from hydrophilic (immediately after oxygen plasma exposure) to hydrophobic (a process achieved by oxygen plasma treatment). This is indicated by a gradual methylation and dehyroxylation with post exposure relaxation time. Non specific binding of nucleic acids has been further evaluated on this surface with fluorescence characterization. The micro-pumps, PCR chamber and capillary electrophoresis have been designed fabricated and tested. A variety of physical processes like mixing, pumping and valving of fluids at the microscopic length scale needed at various points in the analyzer have been achieved. For fabrication of the device, a regime has been developed for bonding PDMS surfaces to a variety of substrates (silicon in the present case). The unique heater design formulated by our team for thermal cycling of the PCR micro-chamber has extremely short ramp-up and down times at a low operating power of 6-watts. We have successfully achieved a compression in the cycle time by a factor of ten from the conventional PCR system. One requirement of the DNA assay posed by its intended field applicability is the need for operating at low powers. One problem with the current capillary electrophoresis assays is a use of extraordinarily high DC voltages. We have developed a protocol of doping agarose gels with platinum nanoparticles which change the overall conductivity level. The doping process also increases the dielectric constant of agarose. Due to this effect we have observed an almost two fold increase in the mobility of nucleic acid stains. This provides us a future direction of using this conducting gel matrix for low voltage capillary electrophoresis. The stain resolution does not get altered due to the dopant. The successful development of our lab-on-a-chip device will have several advantages over conventional bench top systems, which primarily include an overall reduction in size, reduced use of reagents, decreased power requirements, increased speed and accuracy of analysis, and increased portability for field use. We envision this assay as a highly sensitive analyzer tool with a capability to pick-up trace samples with high accuracy.
I 4
SECOND HARMONIC GENERATION IN COPPER NANOPARTICLES
Manabendra Chandra and Puspendu K. Das
Department of Inorganic and Physical chemistryIndian Institute of Science
Bangalore 560012, India
Email: [email protected]
Linear and nonlinear optical properties of metal and metal oxide nanoparticles are
important for futuristic application in the area of optical sensors and photonic devices. We
have synthesized copper nanoparticles (CNP) of four different sizes (5-55 nm) by laser
ablation in isopropanol. Their first hyperpolarizabilities (β) have been measured using the
hyper-Rayleigh scattering (HRS) technique. We find that their β value increases with particle
size. The size dependence of β indicates that the second harmonic is generated at the particle
surface and not in the bulk. Polarization resolved HRS experiments have been utilized to
probe the origin of the optical nonlinearity in the CNPs and also to investigate whether the
various (dipolar and quadrupolar) contributions to the second harmonic signal is separable in
terms of their origin.
I 5
MULTIMODAL CERAMIC NANOVECTOR
Sandwip K. Dey
School of Materials, Center for Interventional Biomaterials, and Department of Electrical
Engineering Arizona State University, Tempe, Arizona 85287-6006
Email; [email protected]
Drug delivery platforms based on nano-sized geometries (aka nanovectors) promise a
revolutionary impact on the diagnosis and therapy of various types of cancers and diseases.
To date, polymeric nanovectors (e.g., nanoparticles, nanospheres, nanocapsules,
nanosuspensions, micelles, liposomes, and dendrimers) have been the focus of intense
research. Since the mid-19th century, inorganic layered double hydroxide (LDH) ceramics
are used for a variety of applications including antacids, catalysts, anion exchangers, and
adsorbents. The intercalated anion, within the interlayer space between the cation hydroxide
layers, can be readily exchanged with a variety of negatively charged bio-molecular agents
such as carboxylic acids, amino acids, nucleoside phosphates, proteins, DNA, ATP, vitamins,
and drugs. Therefore, since 2001, bio-hybridized LDH nanoparticles (or LDHNs) have been
evaluated as a passive vector (administrable via the intravascular or pulmonary route) for
drug and non-viral gene delivery, but its development is at a stage of infancy. To be
competitive with alternate platforms, research on LDHN-based nanovectors must focus on
safety, active targetability, and efficacy. Moreover, it is imperative to build in multimodality
with respect to therapy and imaging, while maintaining overall structural simplicity and
economics of synthesis. This presentation will first specify the advantages of LDHN as a
nanovector for passive targeting, as well as issues in and attributes of LDHN for active
targeting. The judicious selection and synthesis of physiologically relevant LDHN
compositions will be discussed. Next, the surface activation of LDHN, a critical first step
towards surface functionalization for active targeting, will be illustrated. Finally, a few
strategies to build in multimodalities will be described and preliminary experimental results
will be presented.
I 6
INTEGRATED SYSTEMS FOR MANUFACTURING AT THE
NANOSCALE
Placid M. Ferreira
Department of Mechanical Science and EngineeringCollege of Engineering,
University of Illinois, Urbana-Champaign 1206 W. Green Street, Urbana IL, 61801-2906
Email: [email protected]
Nanoscience – the ‘science of the small’ – produces stunning revelations that, almost
daily, redefine the realm of the possible. Yet, the manufacturing processes and systems to
transform this new knowledge into technologies and products that benefit us in our daily life
is a crucial missing element. At Illinois, the Nanoscale Chemical-Electrical-Mechanical
Manufacturing Systems (Nano-CEMMS) Center, a NSF-sponsored Nanoscale Science and
Engineering Center (NSEC), is exploring and developing new methodologies and tools that
exploit chemical, mechanical, and electronic phenomena and processes for manufacturing at
the nanoscale.
This talk is a broad overview of the research and programs within the Center. The
paradigms and processes it attempts to develop by integrating the capabilities of large arrays
of nano-fluidic(molecular gates) and other elements with nanopositioning and sensing will be
discussed. The talk will use the emerging trend of heterogeneous integration in product and
device development to motivate a set of processes that allow for the building of
nanostructures of different materials and their integration into unusual applications. A few
novel processes and technologies that emerge out from the research in the Center will be
described along with the application to biological and chemical sensing.
I 7
APPLICATION OF INNOVATIVE FLUIDICS APPROACHES FOR AIR
AND LIQUID BASED BIOLOGICAL POINT DETECTORS.
Bob Barton, Bob Collins, Alex Freeman, Juan Martinez, Kevin King, Frank
Annecchini, Robert Huebner, Linda Siemann and Roger Starnes.
Midwest Research Institute, Kansas City, Missouri 64110
Email: [email protected]
Midwest Research Institute (MRI) has developed innovative fluidics systems to
support both air and liquid based biodetectors that it is developing for government clients.
While the two projects presented here are dissimilar in some aspects, they share a need for
innovative solutions to fluid flow issues.
In the first program, we are developing a compact flow cytometry system that can be
used to detect toxins in liquid food products for DHS. The fluidic issue is mixing in compact
low volume, sorting of targeted molecules and to develop an instrument that is low cost. The
solution involves magnetic movement of beads as well as electrostatic precipitator.
The second program involves developing air sampler for use in a proprietary system.
The fluidic issue is that the system is operated in a fast moving air stream with fixed inlet
fluid velocity. We have used Computational Fluid Dynamics to design inlet to decelerate
flow and selectively target bioparticles for sorting. The simulations are further compared
against data.
The presentation highlights both the common and different elements of both of these
approaches, discusses both modeling results and experimental data. Conclusions will be
drawn regarding system efficiencies and design issues to meet the application challenges.
I 8
SYNTHESIS OF NANOSTRUCTURED SPINTRONIC MATERIALS
USING PULSED LASER DEPOSITION
K. Ghosh1, L. Fadiga1, C. Vera1, M. Summers1, S. Pulugam1, S. Manchiraju1, N.
Mamidi1, T. Kehl1, S. Guha2, R. Gupta1, K. Manivannan1, and P. K. Kahol1
1Department of Physics, Astronomy, and Materials Science, Missouri State University,
Springfield, MO 65897 2University of Missoui-clumbia, Department of Physics and Astronomy, Columbia, MO
65211 Email: [email protected]
Our research activities address basic issues on growth and characterization of nanostructured materials and fabrication of devices using these materials. Pulsed Laser Deposition (PLD) is an excellent technique to grow nanostructures of starting from simple metals such as gold, silver, and platinum to complex materials such as high Tc oxide superconductors, ferroelectrics, high dielectrics, compound semiconductors, and polymers. Using PLD technique we have successfully grown various nanostructured materials on surfaces such as metals (Au, Ag, and Co), alloys (Fe-Ni), dielectrics (SrTiO3), and compound semiconductors (ZnO). My presentation will focus more on oxide based nanostructured spintronic materials for technological applications such as (1) electro-optic switches1, (2) ultra-sensitive magnetic field sensors2, (3) spin-polarized solar battery3, and (4) quantum-based logic and memory for high speed computationi. Spintronics, a new approach to electronics, is an emerging field based on the up and down spins of the charge carrier rather than on the electrons and holes as in traditional semiconductor electronics. We have grown high quality nanostructured spintronic materials such as Mn and Co doped ZnO dilute magnetic semiconductors (DMS) on various substrates at various conditions using PLD. The structural, electrical, optical, and magnetic properties of these nanostructured materials have been investigated using various characterization techniques such as X-ray diffraction, Raman spectroscopy, Atomic Force Microscope, and magto-transport measurement. Work partly supported by a National Science Foundation Grant # DMR-0321187 to Kartik Ghosh. References 1. S. A. Wolf, “Spintronics: A spin based Electronics vision for the future”, Science 294, 1488 (2001). 2. D.D. Awschalom and J.M. Kikkawa, “Electrical Spin and Optical Coherence in Semiconductors”, Physics Today 52, 33 (1999). 3. Igor Zutic, Jaroslav Fabian, and S. Das Sarma, “Proposal for a spin-polarized solar battery”, Appl. Phys. Lett. 79, 1558 (2001). 4. Semiconductor Spintronics and quantum computation” edited by D. Loss and N. Samrath, Springer Verlag, 2002.
I 9
SELF-ASSEMBLING OF AU AND AG NANOPARTICLES USING
HYDROGEN BONDING Keisaku Kimura*, Yang Yang, Hiroshi Yao, and Seiichi Sato
Graduate School of Material Science, University of Hyogo There is a considerably increasing interest in the field of nanometer-sized substances such as surface
modified nanoparticles, nanodiscs and nanowires due to their notable electronic and optical properties based on the quantum size effect. Designing and fabrication of macroscopic architecture using these nanometer-sized materials as a constructing block will be a next target in the coming nanotechnology era. There are many reports on the construction of two and three-dimensional superlattices made of metallic nanoparticles, because it will provide a peculiar performance based on collective electronic behaviors resulting from interparticle interactions between neighboring ordered particles. In order to construct super structure from nanoparticles, we can use inherent van der Waals attractive force, static coulombic forces, and hydrogen bonding force. Rapid evaporation of organic solvent on solid substrates is a commonly used strategy for providing a three-dimensional architecture from alkane thiol protected metallic nanoparticles. In this case, van der Waals attraction is a main force to bind particles. We have developed a new class of superlattices at an air/water interface by virtue of hydrogen bonding interactions under an equilibrium condition [K.Kimura, S.Sato, H.Yao, Chem.Lett., 2001, 372], contrast to regular lattices by spontaneous evaporation of organic solvent with van der Waals force.
Two metallic nanoparticles, gold and silver, were used to construct nanoparticle assemblies at an air/liquid or liquid/liquid interfaces. Three thiols were used as a surface modifier, dicarboxylic acid (mercaptosuccinic acid), amino acid (N-(2-mercaptopropionyl-glycine)), and tripeptide (glutathione reduced form). The formed powdered samples were re-dispersible several times in water without aggregation. The mean particle diameter was typically 3.5 nm (fwhm: 0.4 nm). The crystallization took place in 4-10 days in the presence of an appropriate amount of hydrochloric acid in a sealed vial giving numerous micrometer-sized nanoparticle crystals with clear crystal habit. Vapor diffusion technique was also used to form superlattices from polydisperse powders. Some examples are shown in the following figures.
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I 10
NANOSCIENCE AND NANOTECHNOLOGY RESEARCH AT THE
WILLIAM L. CLAY CENTER FOR MOLECULAR ELECTRONICS AT
THE UNIVERSITY OF MISSOURI-ST. LOUIS
Jimmy Liu
William L. Clay Center for Molecular Electronics
University of Missouri-St. Louis, Missouri 63121
Email: [email protected]
The various research programs in the area of nanoscience and nanotechnology at the
Center for Molecular Electronics of the University of Missouri-St. Louis will be briefly
described. These research activities include study of nanoclusters, nanoparticles and
catalysts, enzymes and proteins, and state-of the-art nanocharacterization initiatives. The
future focus of the CME programs will be discussed.
I 11
DENSITY FUNCTIONAL THEORY: FROM CONVENTIONAL BULK
TO NANOPOROUS MATERIALS
Julia E. Medvedeva
Department of Physics, University of Missouri – Rolla
Email: [email protected]
Modern computational approaches based on density functional theory
(such as the full-potential linearized augmented plane wave (FLAPW), linearized muffin-tin
orbital (LMTO) and Dmol methods) form a powerful framework for the first-principles
modeling of the structural, electronic, magnetic and optical properties of materials. The
increase of computer power as well as the development and implementation of new
algorithms greatly expand the range of the materials which can be treated. Currently, we are
beginning to understand the properties of complex structures such as nanoporous solids and
polymers. I will present my contribution to the field and possible extensions.
I 12
CONTRAST-ENHANCED RADIOTHERAPY OF CANCER
Michael D. Weil a, Kevin N. Morris a, Rainer M. Malzbender a, Ronald M. Bright b, Steven M. Roberts c and Bradley R. Schmidt b
a Sirius Medicine, LLC, Fort Collins, CO USA b VCA – Veterinary Specialists of Northern Colorado, Loveland, CO USA
c Animal Eye Center, PC, Loveland, CO USA Email: [email protected]
Contrast-enhanced radiotherapy (CERT) utilizes previously neglected effects of x-rays absorbed by contrast agents. Resulting secondary ionizing radiation transfers significant energy and damages a limited volume. By concentrating contrast in a lesion, a lethal radiation dose can be delivered quickly to a tumor with minimal toxicity to nearby tissue. Therefore, CERT should safely create tumor debris and could be a useful adjuvant for immunotherapy. We wanted to evaluate toxicity and efficacy of CERT alone and combined with an immune modulator in parallel human and canine clinical studies. In addition, we sought to follow molecular response in tumor aspirates during treatment. Small lesions and post-operative tumor beds with positive resection margins were treated with one CERT dose alone. Locally advanced and metastatic spontaneous canine tumors were treated with one CERT dose followed by continuous infusion or intratumoral injection of hGMCSF immunotherapy for 3 days. Tumor aspirates were analyzed by RT-PCR using a panel of canine genes. We treated advanced cancers in 43 dogs using CERT without toxicity. There were no recurrences in the 13 post-operative tumor beds treated with CERT alone. Of 27 dogs treated with CERT plus hGMCSF, approximately 70% had significant local responses and immune infiltrates. There has been no evidence of anti-tumor immunity against distant disease. Thus far, there are 2 dogs without evidence of recurrence more than 1 year after treatment. Employing intratumoral injection of commercially available contrast agents, CERT has clinical efficacy with minimal toxicity when used alone or in combination with immunotherapy for advanced canine malignancies. Response was not associated with specific pathology or putative radiosensitivity.
I 13
NANOMEDICINE IMPROVES DRUG SAFETY AND EFFICACY
Hayat Onyuksel
Department of Biopharmaceutical Sciences and Bioengineering,
University of Illinois at Chicago, Chicago IL 60612
Email: [email protected]
One major problem faced with cancer chemotherapy is the dose limiting side effects
of the medication to the healthy cells. To address this issue we have developed a novel
nanomedicine that is composed of sterically stabilized phospholipid mixed micelle (SSMM)
that can solubilize water insoluble anti-cancer drug, paclitaxel (P) in its core and be targeted
to the cancer tissue both by passive and active mechanisms. Mixed micelle is 15 nm in size
and composed of a PEGylated lipid (DSPE-PEG 2000) and phosphatidylcholine. It also has a
targeting ligand (vasoactive intestinal peptide, VIP) on its surface to specifically interact with
VIP receptors ( R) that are overexpressed on cancer cells. Drug molecules solubilized in the
micelle, due to the nanosize of the micelle can only extravasate at the diseased site with leaky
vasculature (100nm pores) such as cancer (passive targeting), and interact with VIP-R
(active targeting). Since VIP-R express only at the extra vascular space, and inability of
nanomedicine P-SSMM-VIP to extravasate at normal tissues, the drug can not interact with
vascular cells and healthy extravascular tissues to cause any undesirable side effects. My talk
will demonstrate data on the improved biodistribution and efficacy of paclitaxel on a breast
cancer rat animal model after iv delivery as a nanomedicine, compared to its marketed
product Taxol.
I 14
CHEMICALLY RESPONSIVE NANOREACTOR MATERIALS FOR
BIOLOGY AND MEDICINE
Agnes Ostafin
Department of Materials Science and Engineering & Bioengineering,
University of Utah, Salt Lake City UT.
Email: [email protected]
Nanoscience and nanoengineering will continue to revolutionize medicine, science &
industry offering extraordinary benefits to society in the coming decades. The next
generation of nanomaterials and technologies are already on the horizon. One of these
emerging areas is nanoreactor science and engineering which focuses attention on physical
and chemical processes in small confined spaces, and how these spaces can be engineered for
optimum effect and to interact with the environment. These materials can lead to smarter,
more functional products, and harnessing them for the lifesciences
and medicine is expected to lead to new therapies, diagnostic capabilities. Some examples
include nanoshells for biocatalysis and sensing of oxidants and nanofactories for PCR. This
presentation will review the development of some of these materials, the effect of
confinement on chemical and photophysical procesesses, and applications where these
materials can be highly advantageous.
I 15
FIRST-PRINCIPLES STUDY OF BORON NANOSTRUCTURES:
SHEETS AND NANOTUBES
Ravindra Pandey
Department of Physics, Michigan Technological University, Houghton, MI 49931
Email: [email protected]
Understanding of the structural stability, electronic properties and chemical bonding
of boron nanotubes can be set as a baseline for the evolutionary changes from carbon
nanotubes to hybrid CxByNz nanotubes to boron-nitride nanotubes. In this study, we explore
structural stability, electronic properties and chemical bonding of boron sheets and nanotubes
using first principles periodic approach. The calculations predict the stability of a novel
reconstructed {1221} sheet over the ‘idealized’ hexagonal {1212} sheet. Nanotubes formed
by wrapping the {1221} sheet show a curvature-induced transition in their electronic
properties. Analysis of the charge density reveals a mixed metallic- and covalent-type of
bonding in the {1221} sheet and the corresponding nanotubes, as compared to the metallic-
type bonding in the {1212} sheet and its analogues nanotubes.
For the single-walled (SW) boron nanotube, the calculated results predict a ballistic
transport, with a relatively lower resistance of 7 k� as compared to that of single-walled
carbon nanotubes which is calculated to be about 20 k�. It may be attributed to the electron-
deficient nature of boron. It is expected that the present study will initiate further theoretical
and experimental studies on boron nanostructures, which will be helpful in understanding,
designing and realizing boron-based nanoscale devices.
I 16
FUNCTIONAL DENDRITIC MATERIALS AND ORGANIC-
INORGANIC HYBRID MATERIALS
Josh Z. Peng
University of Missouri, Kansas City
Email: [email protected]
Understanding the energy transfer process in light-harvesting dendrimers and
harnessing the energy funnel properties of such dendrimers for solar energy conversion and
multifunctional sensing are some of the major contemporary research focuses. Our research
on light-harvesting materials focuses on conjugated dendrimers with a unique unsymmetrical
branching structure. These dendrimers possess a broad absorption range and an intrinsic
energy gradient from the periphery to the core, naturally suggesting that they may be
efficient molecular antennae suitable for transferring energy from the surface to the core.
The applications of such dendrimers as sensors, nonlinear optical materials, and photovoltaic
materials will be discussed. The presentation will also cover our work on developing new
electrically active hybrid materials where conjugated molecules/polymers are covalently
linked with polyoxometalate clusters.
I 17
GOLD NANOPARTICLE BASED FRET ASSSAY FOR DETECTION
OF DNA HYBRIDIZATION AND CLEAVAGE
Paresh Chandra Ray
Department of Chemistry, Jackson State University, Jackson, MS, USA
Email: [email protected]
We present a gold nanoparticle (Au/NP) based FRET assay to monitor DNA hybridization and the cleavage of DNA by nucleases. The fluorescence of a fluorophore tagged ss-DNA increases by a factor of 80 when it binds to a complementary DNA while the addition of single-base mismatch DNA had no effect on the fluorescence efficiency. We present theoretical and experimental results on dye fluorescence quenching induced by gold nanoparticles of different particle sizes. Fluorescence spectra clearly show that the quenching efficiency decreases by increasing size of the gold nanoparticles or increasing the distance between dye and nanoparticles. The mechanism of size and distant dependence of fluorescence quenching has been discussed. Fluorescence signal enhancement is observed by a factor of 120 after the cleavage reaction in the presence of S1 nuclease. This method has several advantages as follows: i) it is several orders of magnitude more sensitive than the usual gel electrophoresis or HPLC technique and few orders of magnitudes more sensitive than UV assays; ii) one can use this technique for multiple targets DNA damage detection and iii) it is much faster and easier to detect. Our experimental observation paradigm for design of optical based molecular ruler strategies at distances more than double the distances achievable using traditional dipole-dipole Columbic energy transfer based methods. This long-range feature will allow the development of biosensors and homogeneous bioassays that are not possible by using general FRET process e.g. catalytic activities of many enzymes such as HIV proteases and matrix metalloproteiases (MMP) as well as the proteins involved in cellular apoptosis. Given the simplicity, speed, and sensitivity of this approach, the described methodology could easily be extended to a high throughput format and become a new method of choice in all applications that require an assay for DNA hybridization and cleavage. A compact, highly specific, inexpensive and user friendly optical fiber laser-induced fluorescence (LIF) sensor based on fluorescence quenching by nanoparticles has been developed to detect single-strand (ss) DNA hybridization as well as DNA cleavage in femtomolar level. Looking into the future, we expect these compact sensor developments will have important implications in the development of better biosensors and bioassay for application to pathogen detection, clinical analysis and biomedical research. Our observations also point toward the exciting possibility to perform spatially confined detection on array formats of biological recognition, for example, RNA/DNA hybridization or antibody-antigen recognition.
I 18
COMBUSTION SYNTHESIS OF ULTRA-HIGH SURFACE AREA
METAL FOAMS Steven F. Son
School of Mechanical Engineering, Purdue University
Email: [email protected]
The synthesis of low-density, nano-porous materials has been an active area of study
in chemistry and materials science dating back to the first synthesis of aerogels. These
materials, however, are most often limited to silica, metal oxides (e.g., Al2O3) and organic
aerogels (e.g., the resorcinol/formaldehyde type), with the only common elemental material
being carbon, arising from pyrolysis of organic aerogels. Here we report a general method to
access unprecedented ultra-low-density nano-structured monolithictransition-metal foams
utilizing self-propagating combustion synthesis from novel transition-metal complexes
containing energetic ligands with high nitrogen content. In investigating the decomposition
behavior of the high-nitrogen metal complexes, nanostructured metal monolithic foams were
formed having remarkably low densities (0.011 g cm-3) and remarkably high surface areas
(258 m2 g-1). The ability to form monolithic metallic nanocellular porous materials is
presently not possible using conventional methodology, particularly at the densities we have
observed, or with the ease of production. To date, we show foam production obtained via this
method demonstrated with iron, cobalt, copper, and silver metals. I will also briefly discuss
some current nanoscale energetic materials (nanoenergetics) work.
I 19
DEVELOPMENT OF POROUS GOLD AS A SUPPORT FOR
BIOMOLECULE IMMOBILIZATION AND ITERATIVE SYNTHESIS
Keith J. Stine, Alexei V. Demchenko, Kenise Jefferson, Olga V. Shulga, and Maria C.
Parlato
Department of Chemistry and Biochemistry and Center for Molecular Electronics, University
of Missouri - St. Louis, One University Boulevard, Saint Louis, MO 63121.
Email: [email protected]
Porous gold is an attractive nanomaterial that combines features of high surface area
with stability and the prospects for controlled modification by self-assembled monolayers
using thiol attachment chemistry. The material can be prepared by a number of routes
including the reduction of gold salts in a starch matrix, treatment of gold alloys in
concentrated acid, and electrochemical dealloying. The porous gold can be characterized
using SEM, TEM, AFM, and other methods. Our principle goal is the use of porous gold as a
substrate for improved iterative synthesis of carbohydrates for applications in biomedical
assays and other studies. In addition, its application as a support for immobilizing enzymes is
being pursued. To date, we have investigated the immobilization of acetylcholinesterase in a
form of porous gold prepared by dealloying white ‘jewelry’ gold in nitric acid. The activity
of the enzyme in the porous gold support has been studied by spectrophotometric assays and
the KM value determined as a function of treatment time and storage time. The surface of the
material has been characterized using the aforementioned microscopy techniques.
I 20
APPLICATIONS OF MINIATURIZATION SCIENCE IN CELL
RESEARCH Svetlana Tatic-Lucic
Electrical and Computer Engineering, Lehigh University, Bethlehem PA 18015
Email: [email protected]
Whereas MEMS and NEMS systems have been used in biology and medicine for
some time, the last decade has seen tremendous growth in applications of miniaturization
science, specifically in biological cell research. The relative maturity of the MEMS and
NEMS field has been complemented by a flourishing of the life sciences, which has led to
the identification and pursuit of an abundance of possible applications of miniaturization
science in fields such as cell biology and neuroscience.
I 21
Posters: Life Sciences
L 1
FREE ENERGY PROFILE OF SINGLE FILE WATER MOLECULES
IN CARBON NANOTUBES
Bogdan Barz, Lorant Janosi and Ioan Kosztin
Department of Physics, University of Missouri, Columbia-65201
Email: [email protected]
The modeling of molecular transport through nanopores (e.g., channel proteins,
carbon nanotubes, etc.) requires to follow the dynamics of the system with almost atomic
spatial resolution on a macroscopic time scale that is beyond the reach of current all atom
molecular dynamics (MD) simulations. A practical approach to this inherently multiscale
problem is to model the transported molecule as an overdamped Brownian particle that
diffuses along the axis of the pore in the presence of an effective potential of mean force
(PMF) that describes its interaction with the rest of the system. Here we present a new
approach for calculating simultaneously both the PMF and the position dependent diffusion
coefficient of a molecule moving along the axis of a nanopore by employing a small number
of fast non-equilibrium MD pullings in both forward and time reverse directions [1]. The
viability of the method is demonstrated in the case of single file water transport through a
periodic structure of densely packed (6,6) single-walled carbon nanotubes (CNTs) that
connects two water reservoirs. The determined PMF and diffusion coefficient are found to be
in good agreement with the ones calculated by other, less efficient methods.
1. I. Kosztin, B. Barz and L. Janosi, J. Chem. Phys. 124, 064106 (2006).
L 2
A SIMPLE AND FAST CT SIMULATION PROGRAM FOR
ESTIMATION OF CONTRAST FROM NANOMATERIALS.
Evan Boote, Vijayalakshmi Kattumuri, Rajesh Kulkarni, Raghuraman
Kannan,Kattesh Katti
University of Missouri-Columbia, Columbia, USA.
Email:[email protected]
This work is motivated by the desire to have a quick and simple method to estimate the
amount of image contrast expected from varying concentrations of metallic nanoparticles in
computed tomography applications. These nanoparticles may be comprised of a variety of
elements. Some elements recently discussed in literature include gold, silver, gadolinium and
bismuth. The simulation involves the use of commercially available scientific software. A
simulation of the CT scanner has been programmed to properly represent the spectral content
of the x-ray beam passing through the object being imaged. This includes the ability to vary
the kVp and exposure (mAs) in the experiments as well as modification of the slice
thickness. The simulation includes quantum noise as a means of determining detection limits
for concentrations of metallic nanoparticles. The validity of the simulation has been verified
using a series of phantom experiments. The simulation has been extended to allow the
importation of DICOM based CT images and thus to add contrast into regions of the image.
In this manner, a priori predictions of the required concentrations may be obtained before
animal or human studies. Another advantage of this approach is to be able to simulate
varying kV/filter combinations to achieve optimal beam characteristics for dual-energy
applications. Figure 1 is an example of a simple water phantom with gold nanoparticles.
Figure 2 is an example of DICOM image data used in the simulation with simulated gold
nanoparticle concentrations in the prostate.
L 3
L 4
CONTROLLED STIMULATION OF QUANTAL CATECHOLAMINE
RELEASE FROM CHROMAFFIN CELLS USING PHOTOLYSIS OF
CAG IP
S
Biological Engineering1, Dalton Cardiovascular Research Center2, Electrical and Computer
Engin
i elevation, similar to previous reports using different techniques. We co 2+ r-thr y NIH NS048826.
ED CA2+ ON TRANSPARENT INDIUM-TIN-OXIDE MICROCH
ELECTRODEXiaohui Chen1,2, Yuanfang Gao3, Maruf Hossain3, Shubhra Gangopadhyay3,
Kevin D. Gillis1,2,4
eering3, Medical Pharmacology and Physiology4, University of Missouri, Columbia,
MO 65201, USA UV photolysis of caged Ca2+ has been widely used to study the dynamics of Ca2+-dependent exocytosis from living cells. Traditionally this technique is integrated with patch-clamp techniques and/or carbon-fiber amperometry, which are labor-intensive and low-throughput. Using photolithography and other microfabrication techniques, we have developed devices with transparent indium-tin-oxide (ITO) electrodes to detect quantal catecholamine release from adrenal chromaffin cells. A 100 nm – thick ITO film was sputter-deposited onto glass coverslips, which was then patterned into working ITO electrodes (15 µm by 35 µm) using photolithography and wet-etching techniques. Bovine adrenal chromaffin cells were brought into contact with the working ITO electrodes for recordings. We initially tested cells whose plasma membrane was permeabilized with digitonin to allow loading of the Ca2+ cage NP-EGTA and Ca2+ indicator dyes from the bath solution. One complication of this approach is that photolysis of cage resulted in a large time-dependent background current at the electrochemical electrode. We therefore tested loading cells using acetoxymethyl (AM) ester derivatives of NP-EGTA and Fura-4F. Upon UV photolysis of caged Ca2+, a uniform rise of intracellular Ca2+ concentration within those cells lead to quantal release of oxidizable catecholamines measured amperometrically by the ITO electrodes beneath them. Simultaneously [Ca2+]i was monitored by the Ca2+ indicator dye. We observed a burst of amperometric spikes upon rapid elevation of intracellular Ca2+ concentration and a “priming” effect of sub-stimulatory [Ca2+]i on the response of cells to subsequent [Ca2+]
nclude that UV photolysis of caged Ca is a suitable stimulation technique for higheoughput studies of Ca2+-dependent exocytosis on microfabricated biochips. Supported b
L 5
A GLUCOSE BIOSENSOR ENCAPSULATED IN ERYTHROCYTES
Majed Grant
Department of Biological Engineering, University of Missouri-Columbia,
robes are based on a competitive binding
anoprobes displayed a sensitivity
f at least 0.5 mM below 5 mM and a sensitivity of at least 3 mM above 5 mM, which meets
ur initial requirements for an implantable glucose sensor.
Dweik and Sheila
Columbia 65211
Email: [email protected]
In 2005, the American Diabetes Association (ADA) reported that 20.8 million people
have diabetes, making it the fifth leading cause of death by disease in the USA. The objective
is to focus on the development of glucose sensitive nanoprobes that could be inserted into
erythrocytes, red blood cells (RBC). Glucose oxidase (GOx), dextran, and the fluorescent dye
pairs, Texas Red (TR), and Alexa Fluor 647 (AF 647), were utilized to develop the
nanoprobes.TR, the donor fluorophores, was labeled to dextran while AF 647, the acceptor
fluorophores, was labeled to GOx. The fluorescent p
technique and uses the chemical transduction method of fluorescence resonance energy
transfer (FRET) to detect the presence of glucose.
Dextran binds to GOx, but in the presence of glucose, the donor-dextran gets
displaced from the acceptor-GOx, resulting in a decrease in acceptor fluorescence with a
corresponding increase in donor fluorescence. Experiments were performed using
fluorescence spectroscopy and the results showed that the n
o
o
L 6
RECONSTRUCTION OF FREE ENERGY PROFILES FROM FAST
NONEQUILIBRIUM PROCESSES Forney Michael and Ioan Kosztin
University of Missouri-Columbia,Columbia 65211
Email: [email protected]
In general, to establish the structure-function relationship of nanoscopic biomolecules
one needs to follow their dynamics on mesoscopic time scale that is beyond the reach of
current all-atom molecular dynamics (MD) simulations. A viable approach to this daunting
problem is a multiscale modeling approach that requires as input the detailed free energy
profile [potential of mean force (PMF)] of the system. In the present study we report PMF
calculations based on a recently proposed method [1] that employs fast (~10ns long)
nonequilibrium MD simulations. Our PMF calculation method, which is more efficient than
previously used ones, yielded very good results for the folding/unfolding of deca-alanine and
for the potassium ions transport through the gramicidin A channel protein.
1. I. Kosztin, B. Barz, and L. Janosi (2006), J. Chem. Phys. 124, 064106.
L 7
THEORETICAL PREDICTION OF OPTICAL AND SPECTRAL
PROPERTIES OF PIGMENT-PROTEIN COMPLEXES Janosi Lorant and Ioan Kosztin
Department of Physics, University of Missouri-Columbia, Columbia 65211
Pigment-protein complexes (PPCs) play an important role in photosynthetically
active biological systems and have been the subject to numerous experimental and theoretical
studies. In a PPC the photoactive pigment molecules are held in a well defined spatial
configuration and orientation by a protein scaffold. The optical and spectral properties of
PPCs are determined by (i) the chemical nature of the pigment; (ii) the electronic interactions
between the pigment molecules and (iii) the interaction between the pigment molecules and
their environment. Because the PPCs function at physiological temperature their optical and
spectral properties are strongly affected by thermal fluctuations. This requires simultaneous
treatment of the electronic couplings between pigments and the effect of thermal disorder.
Here we present a general approach for predicting linear absorption (OD) and circular
dichroism (CD) spectra of PPCs with known high resolution structure. In contrast to previous
empirical models, our model, which combines molecular dynamics, quantum chemistry and
many-body theory, has no fitting parameters. The proposed method was used to calculate the
OD and CD spectra at room temperature of the aggregates of bacteriochlorophyll-a(BChl-a)
molecules in the light-harvesting antenna complexes LH2 from two purple bacteria: Rs.
Molischianum and Rps. Acidophila. The obtained results were found in surprisingly good
agreement with the available experimental data.
L 8
LONGITUDINAL NANOSTRUCTURE STUDY OF THE ISLET IN THE
NOVEL HIP RAT MODEL OF TYPE 2 DIABETES MELLITUS
Poorna R. Karuparthi and Melvin R Hayden
Department of Endocrinology and Diabetes, University of Missouri – Columbia
Email: [email protected]
Diabetes has now become a high profile public health concern in its own right, due to
the escalating epidemic of diabetes in older people, and the emergence of type 2 diabetes in
children. The number of people with diabetes worldwide is set to double in the next 20 years,
as a result of increasing obesity and longevity. The transgenic human islet amyloid
polypeptide (HIP) rat model has emerged as a new model for the study of type 2 diabetes
mellitus (T2DM). The transmission electron microscope was utilized to study the
longitudinal cellular and extracellular morphological changes within the islets of this model
at 4, 8 and 14 months of age. It has been previously demonstrated that the 2, 5, and 10 month
HIP model has no diabetes, impaired fasting glucose and diabetes respectively.
The 4 month old HIP model demonstrated an abundance of β-cells and insulin
secretory granules with significant pericapillary and inter-β-cell islet amyloid deposition.The
8 month model demonstrated smaller islets with extensive islet amyloid deposition and
marked changes of beta cell apoptosis. The 14 month model demonstrated islet and beta cell
atrophy with even greater amounts of extracellular islet amyloid as compared to the 4 and 8
month old models. Functional beta cells were sparse and when found seemed to be associated
with intra islet adipose deposition. Mean blood sugars were 87, 123, 187 and 244 mg/dL in
the Sprague-Dawley control (SDC), 4, 8 and 14 month HIP models respectively.
Longitudinal changes in cellular and extracellular ultrastructure morphology may
provide investigators new information to further evaluate this exciting new animal model of
T2DM, the role of islet amyloid in T2DM and to better understand the progressive nature of
this chronic-epidemic disease.
L 9
NANOENGINEERING OF AMINOSUGAR FUNCTIONALIZED GOLD
NANOPARTICLES FOR SURFACE TARGETING OF CANCER CELLS
Kavita Katti, Vijaya Kattumuri, Kattesh V. Katti, and Raghuraman Kannan
Departments of Radiology and Physics, Universiy of Missouri-Columbia, MO 65212
E-mail: [email protected]; [email protected]
The role of aminosugars, mannosamine, in selective surface targeting of human
cancer cells by converting it into sialic acid in experminental animals is well known.
However, its significance in developing new aminosugar based imaging agents (CT) for
cancer is still in infancy. Toward our overall objective of developing cancer specific new X-
ray computer tomographic (CT) agents, we are currently exploring the imaging capabilities
of functionalized gold nanoparticles. Our recent research efforts on the design and
development of novel strategies for the production a library of AuNPs, have culminated in a
one-step synthetic protocol for carbohydrate functionalized AuNPs. Furthermore, this
synthetic protocol can be extended for surface conjugating AuNPs with aminosugars. In the
present study, we show for the first time, that AuNP-mannosamine conjugate can be
synthesized using non-toxic chemicals via a single step conjugation method. Details on the
synthesis and properties of carbohydrate, and aminosugar functionalized AuNPs and their
potential application in targeting human cancer cells will be discussed in this poster.
L 10
SYNTHESIS AND IN-VITRO STUDIES OF GLYCOPROTEIN
LABELED GOLD NANOCHAIN
Vijaya Kattumuri†, Kavita Katti§, Raghuraman Kannan§, Meera Chandrasekhar† and
Kattesh Katti†§
†Department of Physics and Astronomy, §Department of Radiology,
University of Missouri – Columbia Email: [email protected]; [email protected]
Due to their size and interesting chemical, electronic and optical properties,
biocompatible gold nanoparticles have gained considerable attention in recent years for
potential applications in nanomedicine. In particular, the prospective use of gold
nanoparticles as contrast enhancement agent in X-ray Computed Tomography (CT) for early
diagnosis of specific tumors is being extensively researched. The degree of X-ray contrast is
limited by the number of gold nanoparticles that can be localized at the target tumor/cancer
site. One way to augment the localization of nanoparticles at the target tissue is to utilize gold
nanochains that hold more number of nanoparticles. Therefore, there is a need to develop
biocompatible gold nanochains that are in-vivo stable for their plausible use in non-invasive
in-vivo medical imaging modalities. We herein present a novel synthesis protocol to generate
biocompatible gold nanochains labeled with glycoproteins. The nanochains formation is
monitored by absorption and Transmission Electron Microscopy (TEM). The integrity of
nanochains was tested against saline, cysteine and Bovine Serum Albumin (BSA) conditions
to mimic in-vivo environment.
This work was supported by funds from the National Cancer Institute grant on Cancer
Nanotechnology Platform No:1R01CA119412-01 to Dr. Katti.
.
L 11
SIZE CONTROLLED SYNTHESIS OF MAGHEMITE
NANOPARTICLES FOR BIOMEDICAL APPLICATIONS
Nune Satish Kumar, Aditya Srinath, Kattesh V. Katti and Raghuraman Kannan
Department of Radiology, University of Missouri-Columbia, Columbia, MO
E-mail: [email protected]; [email protected]
Maghemite, popularly known as, Iron oxide nanoparticles, have been widely used for
numerous in-vivo biomedical applications such as magnetic resonance imaging contrast
enhancement (MRI), magnetically guided drug delivery, hyperthermia and cellular therapy.
The size of iron-oxide (IO) nanoparticles is a significant parameter that influence and control
their physical, chemical, and tumor targeting properties. Recent studies have demonstrated
that manipulation of size and composition of nanoparticles will yield most favorable uptake
within the tumor for MRI imaging applications. Despite the huge biomedical importance
synthetic strategies for producing different sized IO nanoparticles are limited. The paucity of
production methods is mainly attributed to their synthetic difficulty. It has been a scientific
and technological challenge to synthesize the magnetic nanoparticles of customized shape
and size. The control of the size, shape and composition of nanoparticles depends on the
type of salts used, pH, and ionic strength of the media. Herein, we present the synthesis of
library of IO nanoparticles. Details of synthesis, TEM measurements and size distribution
analysis are discussed in this poster.
L 12
BIOSENSOR DESIGN AND FABRICATION USING GOLD
NANOPARTICLES
1Craig Vera, 1Kandiah Manivannan, 1Ram Gupta, 1Joe Harkins, 1Mathew Summers, 1Justice Alaboson,2Anjali Manivannan, 1Pawan Kahol, 1Kartik Ghosh
1Department of Physics, Astronomy, and Materials Science, Missouri State University,
Springfield, Missouri. 2Department of Physics, University of Virginia, Charlottesville,
Virginia.
Email: [email protected]
Lately much attention has been given to biosensors as our nation strives for improved
security against potential biological, chemical, and radiological threats. Many biological
materials react to stimuli such as toxins, radiation, and changes in humidity. By fabricating
systems that convert these natural reactions into electrical signals we can create biosensors
with finely tuned properties. Previous research has shown that it is feasible to fabricate
biosensors by attaching gold nanoparticles to the surface of a live bacterium. However, their
sensor was effective for less than one month.1 We are attempting to use similar methods to
create a stable biosensor utilizing Gold nanoparticles.2 Currently we are working on
identifying a non-living biomaterial that would be a viable substitute for the living bacterium
and be sensitive to humidity and external bio-agents.3 We will describe the details of our
design and discuss the feasibility of fabricating such a biosensor. (Supported by NSF Award
#DMR-0321187 to K. Ghosh and a Sabbatical Leave Award to K. Manivannan.)
1. V. Berry and R. F. Saraf, “Bacterium: An Avenue to Fabricate Electronic Devices,” Angew
Chem. Int. Ed. 44, 6668, 2005.
2. A. Manivannan, “Growth and Characterization of Nanomaterials,” PROC. 15th NASA MO
Consortium, 2005.
3. K. Manivannan et al., “Design and Fabrication of a Biosensor Utilizing Gold
Nanoparticles,” MAS Conference, April 2006.
L 13
DETECTION OF HIV-1VIRAL ENVELOPE SURFACE PROTEINS
USING QUANTUM DOTS AND FÖRSTER RESONANCE ENERGY
TRANSFER (FRET) IN LIQUID CORE WAVEGUIDES Manor Rosalynn Monique
Department of Biological Engineering, University of Missouri-Columbia, Columbia, MO
Email: [email protected]
The concentration of human immunodeficiency virus (HIV) in blood strongly
influences treatment regimens for HIV positive patients. Currently, no HIV viral load
detector exists for technology limited countries. Polymerase chain reaction (PCR) and other
RNA assays are increasingly sensitive however they need extensive equipment and also
produce false-positive results. A novel, dual binding biosensor for the analysis of HIV viral
load is reported here. Gp120, found on the surface of the viral envelope, is detected through
dual-receptor sensing via Förster resonance energy transfer (FRET). Monoclonal antibody
gp120 (mAb gp120) and soluble CD4 are conjugated to CdSe/ZnS quantum dots (donor) and
Alexa Fluor dye (acceptor), respectively. Dual docking of the CD4 and mAb gp120 on the
envelope protein permits distant dependent energy transfer, quantifying the presence of the
HIV virus. Dose dependent experiments confirm that an increase in gp120 concentration
results in an increased acceptor emission. Concentrations 0.64 nM of gp120 has been
detected with an 11.3 microliter sample volume. However, self-quenching of multiple dye
molecules at high HIV-1 gp120 concentrations result in a biosensor of low dynamic range.
L 14
PRODUCTION OF GOLD 198/199 NANOPARTICLES FOR
POTENTIAL USE IN DIAGNOSIS AND TREATMENT OF CANCER
V. Rahing, R. Kannan, C. J. Smith, T. Rold, T. Hoffman, K.V. Katti, K. Katti, C. S.
Cutler
MURR, University of Missouri-Columbia, Columbia, MO
Email: [email protected]
Radiopharmaceuticals are used for both imaging and treatment of many kinds of
diseases including bone cancer and non-Hodgkin’s lymphoma. A radiopharmaceutical
consists of a seeking molecule that selectively targets certain cells such as tumorous versus
normal. The targeting molecule is then labeled with a radioactive atom(s) that can either
deliver radiation to the tumor for imaging or for selectively killing the cell. The purpose of
this project is to develop a method of preparing stable radioactive Gold nanoparticles for
potential radio diagnostic or therapeutic applications. The radioactive properties of Au-198
(β- = 0.96 MeV; γ = 411 KeV) and Au-199 (β- = 0.45 MeV; γ = 158 KeV) with their beta
(therapeutic) and gamma (imaging) emissions make them valuable candidates for both
therapeutic and imaging applications. Because of the number of radioactive atoms present in
a nanoparticle potentially a much larger dose could be delivered to the tumor than by
conventional methods.
It is known that tumor tissues have an enhanced permeability leading to increased
cellular uptake of particles up to 400 nm in diameter. This makes Gold nanoparticles an
attractive option with diameters less than 100 nm enabling dose delivery directly to the
cancer cell. Such delivery methods could improve selectivity by increasing the dose
concentration absorbed by the tumor versus other tissues, thus reducing potential side effects.
Additionally, size has been shown to dictate the biodistribution and clearance properties of
these nanoparticles.
Results will be presented on initial studies to fabricate gold nanoparticles and their
biological evaluation in normal mice as well as recent attempts to vary the size of the
particles by varying their parameters of formation.
L 15
CELLULAR SENSING OF FORCE AND GEOMETRY THROUGH
FORCE-DEPENDENT UNFOLDING AND ONCOGENE
PHOSPHORYLATION
Rivera_Lydia and Michael P. Sheetz Department of Biological Sciences, Columbia University, New York, NY 10027
Email: [email protected]
The shape and behavior of mammalian cells is defined by interplay between extracellular signals (physical and chemical) and the cellular responses. In particular, external molecular-level geometry and forces have major effects on cell behavior (Vogel and Sheetz, Nature Rev. Mol. Cell Biol. 7:265, 2006). A prominent example is the rigidity response since transformed cells can often grow on soft agar whereas normal cells require rigid surfaces to grow, i.e. oncogenes are involved in defining cell mechanics (reviewed in Giannone and Sheetz, Trends Cell Biol., 16:213, 2006). Thus, a critical component for cancer is the ability to override the requirement for force production and rigidity response. For most mammalian cells there are relatively few types of motility that are evident from quantitative analyses of rapidly spreading fibroblasts (Dubin-Thaler et al., Biophys. J. 86:1794-1806, 2004). One motile phase that we have studied extensively involves periodic contractions (24 s period) in local regions of the leading edge of the cell (Giannone et al., Cell, 116:431-443, 2004). The periodic signal is carried radially from the cell edge toward the center and is part of a general mechanism for rigidity-directed movement and pathfinding. Another motile phase involves the movement of individual collagen fibers in a hand-over-hand fashion (Meshel et al., Nature Cell Biol. 7:157-164, 2005) where the geometry of the fiber is being sensed. Rigidity and geometry responses in these systems are dependent upon the cytoskeleton and force-dependent tyrosine phosphorylation through oncogenes (Sawada and Sheetz, J Cell Biol. 156:609-15, 2002; Tamada et al., Developmental Cell, 7:706-718, 2004) that appears to involve unfolding of cytoplasmic kinase substrates, particularly p130Cas (Sawada et al. ). Recent studies indicate that the cell rigidity response requires RPTP� and occurs preferentially at the leading edges of moving cells through forces of 10-20 pN generated by displacements of 50-100 nm (Jiang et al., Biophys J. 90:1804, 2006). The mechanism of rigidity response involves recruitment of Fyn kinase in a palmitoylation-dependent process and the phosphorylation of p130Cas at the leading edge (Kostic and Sheetz, Mol Biol Cell, 17:2684, 2006). A displacement mechanism for the rigidity response is postulated. We will discuss how cells organize motility tools in motile phases (Döbereiner et al., Phys. Rev. Letters. 93:108105-1-4, 2004) in a dialogue with the environment to define cell morphology and behavior over time.
L 16
SYNTHESIS AND APPLICATION OF NANOSTRUCTURED
MATERIALS AND BIOMEDICAL MATERIALS
Andrew Charles Ritts,1 Joseph McCrate,2 Matthew Jon Pais,2 Liang Chen,2
Jian Shi,2 Qingsong Yu1 and Hao Li2*
Chemical Engineering Department,1 Mechanical Engineering Department,2
University of Missouri-Columbia
Email: [email protected]
Research in the Nanomaterials and Biomaterials Laboratory (NBL) at the University
of Missouri-Columbia focuses on synthesis, characterization, and application of novel
nanostructured materials and biomedical materials with advanced properties. Our research
interests integrate a variety of materials, including ceramics, polymers, thin films, nanotubes,
nanowires, and composites, within the general context of materials science, mechanical
engineering, electrical engineering, and tissue engineering. The key rationale of our research
is that 1) materials and systems with nanoscale structures and components exhibit novel and
significantly improved physical, chemical, and biological properties, and 2) the systematic
organization of matter on the nanometer length scale is a key feature of biological systems.
Some of our current research results include: Horizontal Growth of Nanotubes and
Nanowires; Development of Nanotube and Nanofiber Reinforced Composites;
Nanocomposites as Hard Tissue Implants or for Hard Tissue Engineering.
L 17
SCANNING ION CONDUCTANCE MICROSCOPY REVEALS
CLUSTERED PUNCTATE DEPRESSIONS AND VALLEYS IN THE
PLASMA MEMBRANE DURING STIMULATION OF EXOCYTOSIS
FROM CHROMAFFIN CELLS
Wonchul Shin1,2 and Kevin D. Gillis1,2,3
Biological Engineering1, Dalton Cardiovascular Research Center2, and Medical Pharmacology and Physiology3, University of Missouri, Columbia, MO 65211, USA
Email: [email protected]
The rate and extent that vesicles lose their spherical shape and collapse into the surface membrane upon exocytosis is controversial. We used Scanning Ion Conductance Microscopy (SICM) to image changes in surface membrane morphology upon stimulation of exocytosis from bovine adrenal chromaffin cells. SICM is an excellent scanning probe microscopy technique to scan living cells because the pipette probe does not touch and thus deform the membrane surface. We used a distance modulation method of SICM to continuously image cells before and during stimulation with a depolarizing bath solution containing an elevated K+ concentration. We found clustered punctate depressions (100 – 600 nm wide by 40 – 100 nm deep) in some cells, whereas others exhibited extended valley-type structures (widths of > 1000 nm). We observed punctate depressions in 9 out of 56 experiments and valleys or other large morphological changes in 36 out of 56 experiments. Depressions were not seen if Ca2+ was excluded from the depolarizing bath solution. Images that contained punctate depressions were clustered in groups of 2-4 depressions. The average distance between depressions was 0.93 µm for 3x3 µm image sizes and 1.12 µm for 5x5 µm images. Monte Carlo simulations demonstrated that a random clustering of depressions would have mean separations of ~1.56 and 2.6 µm, respectively for 3x3 and 5x5 µm image sizes. Combination of SICM with fluorescent tags of vesicle membrane proteins will be necessary to determine if the depressions indeed reflect sites of exocytosis and if the disappearance of depressions is due to flattening of fused membrane on the cell surface or re-uptake into the cell. Supported by NIH NS40453.
L 18
DEVELOPMENT OF AN OPTICAL NANOBIOSENSOR FOR
DETECTION OF PRRS
R Cody Stringer1, Sheila Grant1, Susan Schommer2, Daniel Hoehn1
1Dept. of Biological Engineering, University of Missouri, Columbia, MO. 2Dept of
Veterinary Pathobiology, University of Missouri, Columbia, MO
Email: [email protected]
Current methods for the detection of Porcine Reproductive and Respiratory Syndrome
(PRRS) Virus are often lengthy procedures that must be carried out in a laboratory setting or
are meant to detect the antibodies produced by the infected animal, making detection difficult
in animals that have been vaccinated against the virus. Because PRRS virus is a quickly
spreading and easily adaptable virus, there is a need for expeditious detection in order to
quarantine infected animals and halt the transmission of the virus. Therefore, a sensor that
could quickly detect PRRS virus in a field application would be highly advantageous. The
use of a nanosensor architecture applied to an optical biosensor system could carry out this
function. The sensor architectures currently being developed utilize a PRRS virus
monoclonal antibody conjugated with a fluorescent dye and bound to Protein A, which is
conjugated to either a quantum dot or a gold nanoparticle. When exposed to the PRRS virus,
a conformational change in the antibody causes a change in the fluorescent spectrum of the
nanosensor. Preliminary results have shown that the PRRS virus can be detected with both
the quantum dot- and gold nanoparticle-based architectures. Consequently, it can be
concluded that the nanobiosensor method is a feasible technique for PRRS virus detection.
L 19
APPLICATION OF ATOMIC FORCE MICROSCOPY AND
FLUORESCENT MICROSCOPY IN STUDY OF THE
MECHANOTRANSDUCTION OF VASCULAR SMOOTH MUSCLE
CELLS Zhe Sun1, Luis A. Martinez-Lemus1,2, Gerald A. Meininger 1,2
1Dalton Cardiovascular Research Center, and 2Department of Medical Pharmacology and
Physiology, University of Missouri-Columbia, Columbia, MO 65211
Email: [email protected]
Integrin mediated mechano-transduction in vascular smooth muscle cells (VSMC) plays an important role in arteriole physiological functions, such as establishing the basal myogenic tone and regulation of vascular resistance. To understand the mechanism of integrin-mediated VSMC mechano-transduction, we used an atomic force microscope (AFM)
to apply defined pulling forces on VSMC (isolated from rat cremaster arteriole, 70-100 µm diameter) through integrin-fibronectin (FN) adhesions. AFM probes were configured with
fused borosilicate beads (2 µm diameter) at the tip. After coating with FN, the AFM bead tip was brought into contact with VSMC to form adhesions, and step increases of up-ward (z-axis) pulling force (800~2000 pN) were then applied to VSMC through the bead. VSMC responded to the applied force by developing a counterbalancing downward force, however, without an apparent increase of intracellular calcium concentration. Similar force-generating response was also observed in VSMC pre-loaded with BAPTA. Immunofluorescent microscopy studies indicated that FN-coated beads induced clustering of a variety of integrins and formation of actin filament network around the bead. Treatment of the cells with the actin filament depolymerizing compound (cytochalasin D) blocked the VSMC mechanical response, whereas an actin filament stabilizing compound (jasplakinolide) enhanced the VSMC mechanical response. Further studies with ML-7, a specific blocker for myosin light chain kinase (MLCK), also abolished the cellular force response. Similar pulling experiments with other extracellular matrix proteins (collagen I, vitronectin, or laminin) failed to induce a mechanical response of VSMC, however, beads coated with these proteins were able to form similar cytoskeletal connections on VSMC. Collectively, these results suggested that the VSMC mechanical response could be mediated by specific FN-related cell signaling, and that the response was actin and MLCK dependent.
L 20
IMMOBILIZATION OF PEPTIDES ON QUANTUM DOTS FOR THE
DEVELOPMENT OF A PROTEASE BIOSENSOR
Craig Weilbaecher, Darcy Lichlyter, and Sheila Grant Biological Engineering, University of Missouri-Columbia
Email: [email protected]
We have been developing a new optical biosensor platform for the detection of
medically relevant enzymes. Three different peptide sequences have been synthesized as
trypsin substrates that are designed to be immobilized onto the surface of functionalized
quantum dot. The peptides were synthesized with the fluorophore, fluorescein attached to
the opposite end of the peptides to allow for fluorescence resonance energy transfer (FRET)
sensing. Sensors utilizing FRET switch their fluorescence wavelength between the donor
(QD) and the acceptor dyes (Fluorescein) as distance between the two changes. When the
peptide is cleaved by trypsin, the donor and acceptor fluorophores are separated, resulting in
a detectable change in fluorescence.
The peptides were immobilized onto quantum dots using the EDC/s-NHS technique.
Different molar ratios of peptide to quantum dot have been selected to determine efficient
coupling. Quantum dots were utilized in order to increase the surface area for the peptide
immobilization and because of the unique advantages of nanocrystalline particles. The
substrates were then exposed to various concentrations of trypsin. Preliminary results
showed that the trypsin cleaves the positive peptides resulting in an increase in donor
fluorescence and a decrease in acceptor fluorescence.
L 21
Posters: Material Sciences
M 1
COMPACT POWER GENERATION USING METASTABLE
INTERMOLECULAR COMPOSITE (MIC) MATERIAL
Steven Apperson, Jae Kwon, Rajesh Shende, Andrey Bezmelnitsyn, Rajagopalan
Thiruvengadathan, Shubhra Gangopadhyay
Center for Micro/Nano Systems and Nanotechnology, University of Missouri – Columbia,
Columbia, Missouri 65211
Email: [email protected]
A new class of energetic materials known as metastable intermolecular composites
(MIC) is being studied to develop novel synthesis techniques and unique applications. One
application that has gained a lot of interest from DoD and DOE is power generation. A
unique aspect of MIC materials is the controllability of their combustion rates ranging from
1m/s to ~2700m/s. MIC materials with combustion rates above ~1000m/s have been shown
to produce super-sonic pressure waves, or shock-waves. The shock-waves which are
produced can been used to generate pulsed power in piezoelectric materials. A high-voltage
generator using our material shows higher energy density than one using C4 explosive. Using
5.4mg of MIC material, 96.6 mJ/cm3 is produced in a 1mm PZT disc, whereas a power
generator using 12g of C4 explosive produced only 79.89 mJ/cm3 in a 1mm PZT disc.
M 2
RAMAN SPECTROSCOPIC STUDIES OF SEMI-CRYSTALLINE
POLYFLUORENE UPON THERMAL CYCLING
M. Arif1, C Volz1, M. J. Winokur2, and S. Guha1
1Department of Physics, University of Missouri-Columbia, MO, 2Department of Physics,
University of Wisconsin-Madison, WI
Email: [email protected]
Polyfluorene (PF) conjugated polymers have received widespread attention due to
their facile processing characteristics in combination with strong blue emission, high charge
mobility and excellent chemical and thermal stability which creates great prospect for
optoelectronic device application. Almost all PF derivatives utilize solubilizing side-chain
substituents anchored at the bridging carbon atom to mould explicit molecular level
properties as well as confer new functionality. Thermal cycling of PFs results in distinct
backbone and side chain conformations that lead to improved optoelectronic properties.
Vibrational frequencies and intensities determined by Raman spectroscopy are strongly
influenced by conformations of the main backbone and side chains. Application of Raman
scattering is especially useful in PFs for discerning the families of chain conformers and
structural phases.
Di-octyl substituted PF (PF8) is known to have at least five crystalline phases and
many conformational isomers that depend upon the torsional angles between the fluorene
monomer units. These are further dependent on solvent processing and thermal history. In
this work we present detailed temperature dependent Raman scattering studies of semi-
crystalline PF8 casted from various solvents to investigate phase transitions, molecular
ordering and planar/nonplanar conformations. Side chain conformation as a function of the
crystalline phases can be probed by studying the low frequency region (100-700 cm-1) of
Raman spectra which are strongly impacted by thermal cycling. Our experimental results
combined with theoretical Raman spectra calculation show a distinct conformation of the
alkyl side chains when the polymer is in the alpha crystal phase. Our results are further
compared with x-ray diffraction results.
M 3
GAS STORAGE CAPABILITIES AND STRUCTURE OF
NANOPOROUS CARBON
Jacob Burress, Michael Wood, Sarah Barker,* Carol Faulhaber,* Peter Pfeifer
Physics Department, University of Missouri-Columbia
[email protected], [email protected], [email protected], [email protected],
*Work done at University of Missouri-Columbia as part of the ALL-CRAFT Internship
Program
Networks of fractal nanopores in activated carbon have recently been discovered
(Pfeifer et al., Phys. Rev. Lett. 88, 115502 (2002)). These networks have been studied for the
purpose of methane and hydrogen storage (Alliance for Collaborative Research in
Alternative Fuel Technology, http://all-craft.missouri.edu). We examine the pore structure by
nitrogen and methane adsorption isotherms, small-angle x-ray scattering (SAXS), and
electron microscopy. Methane adsorption isotherms were also used to calculate the
deliverable pressure that a storage tank could supply. The process of creating the activated
carbon is being optimized by Prof. Galen Suppes’ research group (Chemical Engineering
Dept., University of Missouri-Columbia). Methane storage at 34 atm and 2 atm was tested to
facilitate this optimization. Hydrogen storage and hydrogen adsorption isotherms were
investigated at both room and cryogenic temperature (298 K and 77 K respectively).
Currently our best sample stores 0.12 g methane per cm3 mono-lithic carbon at 25 ºC and 34
atm (100% of DOE target).
Support: National Science Foundation (EEC-0438469); University of Missouri; Midwest
Research Institute, Kansas City; G. Ellsworth Huggins Fellowship; U.S. Department of
Education (GAANN); and U.S. Department of Energy (W-31-109-Eng-38)
M 4
SPECTROSCOPIC STUDIES OF NANOPARTICLES AND
NANOSTRUCTURED SURFACES
Himadri Chakraborty
Department of Chemistry & Physics, Northwest Missouri State University
Email: [email protected]
Physics of electronic dynamics of nanoparticles, namely, buckyballs, endohedral
buckyballs, nanotubes, quantum dot nanocrystals etc. is radically different from that of the
electrons in regular atoms and molecules. This is because an electron bound over nanometers
region is far more delocalized than an atomic electron bound within a few tens of pico-meter
(10-12 m). This causes so-called size-quantization in nanosystems, enabling their
spectroscopy rich in novel effects. Our recent photoabsorption studies on some of these
nanoparticles indicate the effect of the systems’ shape and geometry on their response to the
photon field [1, 2]. Furthermore, moving to the condensed matter systems, nanoscopic
structuring on the surface of a metal causes its surface electrons experience an effect of
confinement from size-quantization along the surface plane. Our recent anion scattering
simulations on some vicinally structured surfaces indicate a possible way to map the surface
geometry using the ion beam spectroscopy [3].
References:
1. S.W.J. Scully et al., Phys. Rev. Lett. 94, 065503 (2005)
2. M. Zamkov et al., Phys. Rev. Lett. 93, 156803 (2004)
3. H. S. Chakraborty et al, International Conference of Photon Electron and Atomic Collisions,
Brazil (2005).
M 5
MOLECULAR DYNAMICS SIMULATION OF THE SIZE EFFECT OF
CARBON NANOTUBES ON THE MATERIAL PROPERTY OF A LIPID
BILAYER
Yong Gan and Zhen Chen
*Department of Civil and Environmental Engineering, University of Missouri-Columbia
Columbia, MO 65211, USA
Email: [email protected]
Due to their special features at nanoscale, carbon nanotubes could enter the human
body via certain way. The growing use of carbon nanotubes in practical applications, hence,
prompts a necessity to study the potential health risks of carbon nanotubes. A numerical
study is performed here to investigate the size effect of carbon nanotubes on the bulk
modulus of a lipid bilayer by using the constant surface tension molecular dynamics
simulation procedure. It is found that the size effect is not monotonic with the increase of
nanotube length. An explanation is given based on the atomic interaction between the
nanotube and bilayer involved in the model system.
M 6
DIELECTROPHORETIC FABRICATION OF 1D-NANOMATERIAL-
BASED DEVICES
Lifeng Dong
Department of Physics, Astronomy, and Materials Science, Missouri State University,
Springfield, MO 65897
Email: [email protected]
Due to their unique physical and chemical properties, one-dimensional (1D)
nanostructured materials, such as carbon nanotubes, ZnO nanowires/nanobelts, and NiSi
nanowires, have been extensively studied as building blocks for nanoscale electronics,
optoelectronics, and biosensors. The challenge of realizing the potential applications is to
place the 1D nanostructures onto desirable locations. In this study, electrical field and various
dielectric media were investigated to confine single-walled carbon nanotubes (SWCNT) and
NiSi single-crystal nanowires in between two platinum electrodes. Depending on the
nanotubes/nanowire suspension concentration and electrical field distribution, various
configurations, such as single, chained, and branched nanotubes/nanowires were aligned
between the electrodes. Several alignment mechanisms, including the induced charge layer
on the electrode surface, nanostructure dipole-dipole interactions, and an enhanced local
electrical field surrounding the aligned nanostructures are proposed to explain these novel
dielectrophoretic phenomena on 1D nanostructures. Furthermore, a floating-potential
dielectrophoresis method was successfully developed to achieve controlled alignment of an
individual semiconducting or metallic SWCNT between two electrical contacts with high
repeatability. Experimental results indicate that bundles of nanotubes along with impurities
were first moved into the region between two control electrodes while individual nanotubes
without impurities were straightened and aligned between two floating electrodes. The
measurements for the back-gated nanotubes transistors made by this method displayed an on-
off ratio and transconductance of 105 and 0.3 µS, respectively. These output and transport
properties are comparable with those of nanotubes transistors made by other methods.
M 7
GIANT MAGNETORESISTANCE EFFECT IN ORGANIC-INORGANIC
HETERO-STRUCTURE SPINTRONIC DEVICES
L. Fadiga1, K. Ghosh1, P. Kahol1 and S. Guha2, 1Department of Physics, Astronomy & Materials Science, Missouri State University,
Springfield, MO 65897, 2University of Missouri - Columbia, Department of Physics and
Astronomy, Columbia, MO 65211
Email: [email protected]
Recently, a new field has emerged, called spintronics or sometimes magneto
electronics, which combine both the spin and charge of electrons to obtain devices with new
functionality and increased performance. The advantages of these new devices would include
nonvolatility, increased data processing speed, decreased electric power consumption, and
increased transistor density compared to conventional semiconductor devices. Recently spin
polarized injection has been demonstrated in organic semiconductor OLEDs based on
sexithienyl and CMR manganite, La2/3Sr1/3MnO3 (LSMO), and PEDOT and PFO. Tri-layer
structure of ferromagnetic/organic/ferromagnetic devices has been made using thermal
evaporation, pulsed laser deposition, and spin coating techniques. In this presentation our
recent research activities will be discussed in more details, such as the fabrication, structural
and physical characterizations of various inorganic-organic spintronic devices. Experiments
involving associations of different combinations and thicknesses of materials have been
investigated, and have resulted in better accuracy in the detection of the tunneling in the
organic material and increased spin polarization of the devices through appliance of magnetic
fields. This work is supported by NSF (award # DMR – 0321187).
M 8
MOLECULAR DYNAMICS SIMULATION OF THE SIZE EFFECT OF
CARBON NANOTUBES ON THE MATERIAL PROPERTY OF A LIPID
BILAYER
Yong Gan and Zhen Chen
Department of Civil and Environmental Engineering, University of Missouri-Columbia
Columbia, MO 65211, USA
Email: [email protected]
Due to their special features at nanoscale, carbon nanotubes could enter the human
body via certain way. The growing use of carbon nanotubes in practical applications, hence,
prompts a necessity to study the potential health risks of carbon nanotubes. A numerical
study is performed here to investigate the size effect of carbon nanotubes on the bulk
modulus of a lipid bilayer by using the constant surface tension molecular dynamics
simulation procedure. It is found that the size effect is not monotonic with the increase of
nanotube length. An explanation is given based on the atomic interaction between the
nanotube and bilayer involved in the model system.
M 9
HIGHLY CONDUCTIVE AND TRANSPARENT ZNALO THIN FILM
FOR ORGANIC LIGHT EMITTING DIODES
R. K. Gupta, C. Vera, L. Fadiga, K. Ghosh, and P. Kahol Department of Physics, Astronomy, and Materials Science, Missouri State University,
Springfield, Missouri-65897, USA
Organic light emitting diodes (OLEDs) have attracted much attention for use in the
next generation of display technology. In these devices transparent conductive oxide (TCO)
layer is used as anodes. Although indium tin oxide (ITO) is most widely used as TCOs,
indium is relatively scarce element in the earth’s crust so the cost for production of ITO is
relatively high. In this communication we are reporting the preparation, and characterization
of thin films of Zn0.99Al0.01O. Highly conductive and transparent thin films of Zn0.99Al0.01O
were deposited on the quartz substrate using pulsed laser deposition (PLD) technique. The
target for the PLD was prepared by the standard solid state reaction method. The electrical
and optical properties of these films have been compared with that of ITO and pure ZnO. It
has been observed that the ZnAlO film has transparency comparable to that of pure ZnO and
ITO. The Hall measurements of these films have been carried out at room temperature.
Different parameters such as type of majority carriers, carrier concentration, and mobility
have been calculated. The carrier concentration of ITO, ZnO and ZnAlO was 2.74 × 1020,
1.72 × 1019 and 1.37 × 1020 per cm3 respectively. Al-doped ZnO could be an excellent
transparent conducting electrode for future optoelectronic devices.
M 10
MICROWAVE PLASMA-ASSISTED CHEMICAL VAPOR
DEPOSITION REACTOR: INSTRUMENTATION AND
IMPLEMENTATION FOR CARBON-BASED MATERIALS FOR
ELECTRONIC DEVICES AND BIOSENSING APPLICATIONS*
S. Gupta1, G. P. Vierkant2,, and R. E. Giedd2
1Department of Electrical and Computer Engineering, University of Missouri-Columbia, MO 65211, 2Department of Physics and Materials Science and Center for Applied Science and
Engineering, Missouri State University, Springfield, MO 65897 Email: [email protected]
Chemical vapor deposition techniques prove to be extremely valuable for the
deposition of a variety of technological important materials for diverse applications. One of its variants - Microwave Plasma-assisted Chemical Vapor Deposition (MPACVD) provides invaluable capabilities to synthesize a gamut of carbon-based materials utilizing advanced process control of growth parameters including plasma, power, feedstock gases and their ratio, substrate temperature and so forth. MPACVD growth of carbon-based materials such as diamond offers an excellent alternative to existing silicon technology which is usually limited by intrinsic thermal, mechanical, and electrical properties. While extensive carbon material research has been performed over the last two decades, growth mechanism including nucleation, synthesis, and doping are not yet fully understood. This work will present and discuss the (a) assembly and testing of an ASTeX PDS-18 MPACVD unit for synthesizing advanced carbon materials; poly-/micro-/nanocrystalline diamond films; (b) upgrade of system hardware and software to leverage modern computing and control capabilities while maintaining process safety and performance; and last but not the least (c) process optimization to study growth mechanism and their influence on structure properties with a view to establish microscopic structure-property correlation. Specifically, boron-doped diamond (BDD) will be presented as a case study being used for diverse technological applications such as electronic devices, N/MEMS, and electrochemical microelectrodes for sensing.
*This work is financially supported by ONR Grant while one of the authors (SG) was at the Missouri State University, Springfield. #The other authors (GPV) is a graduate student who conducted his master’s thesis in Materials Science and defended in June, 2006 under the guidance of corresponding author (SG) and REG is a director of the center-CASE. *This work is submitted on behalf of Graduate student by his advisor.
M 11
NANOSCALE SURFACE CHARACTERIZATION WITH NONLINEAR
PARAMETER IDENTIFICATION
Siddharth Hazra, Brian Mann
Mechanical and Aerospace engineering, University of Missouri-Columbia, MO, USA.
Email: [email protected]
The typical approach to identifying nanomechanical properties with indentation
testing relies upon linear oscillator theory. In particular, the model for a linear oscillator is
often imposed to obtain a local contact stiffness and interpret the nanomechanical properties.
However, this can sometimes lead to erroneous information since measurement nonlinearity
is being falsely interpreted as material behavior. The objective of this research is to
demonstrate the need to include nonlinear relationships in the dynamic models for
indentation. Results show that including model nonlinearities can often greatly improve
quantitative nature of an indentation test.
The present work can be divided into a study of the probe mechanics under the
influence of the nonlinear forces and a study of the influence of adhesive and van der Waals
forces. To this end a one-to-one equation between the loading force and contact deformation
between the probe and sample surface is established. Taking the equations for contact
deformation, as established by Schwarz (U. D. Schwarz, 2003), we find an expression for the
contact radius in terms of the probe deflection. This allows analytic calculation of the
linearization error in the force-displacement relationships during contact and also reveals the
amplitudes within which errors increase. This study elucidates the amplitudes and
deformation-depths at which linearization is feasible.
M 12
SIZE CONTROLLED SYNTHESIS OF MAGHEMITE
NANOPARTICLES FOR BIOMEDICAL APPLICATIONS
Nune Satish Kumar, Aditya Srinath, Kattesh V. Katti and Raghuraman Kannan
Department of Radiology, University of Missouri-Columbia, Columbia, MO
E-mail: [email protected]; [email protected]
Maghemite, popularly known as, Iron oxide nanoparticles, have been widely used for
numerous in-vivo biomedical applications such as magnetic resonance imaging contrast
enhancement (MRI), magnetically guided drug delivery, hyperthermia and cellular therapy.
The size of iron-oxide (IO) nanoparticles is a significant parameter that influence and control
their physical, chemical, and tumor targeting properties. Recent studies have demonstrated
that manipulation of size and composition of nanoparticles will yield most favorable uptake
within the tumor for MRI imaging applications. Despite the huge biomedical importance
synthetic strategies for producing different sized IO nanoparticles are limited. The paucity of
production methods is mainly attributed to their synthetic difficulty. It has been a scientific
and technological challenge to synthesize the magnetic nanoparticles of customized shape
and size. The control of the size, shape and composition of nanoparticles depends on the
type of salts used, pH, and ionic strength of the media. Herein, we present the synthesis of
library of IO nanoparticles. Details of synthesis, TEM measurements and size distribution
analysis are discussed in this poster.
M 13
NOVEL SIO2 COATINGS FROM BIOMINETICS\
Bob Heiman
Shiloh Innovation LLC, OH 43342
Email [email protected]
Biomimetic Engineering has been defined as processing techniques inspired by
biologicial processes. Diatoms build complex structures from silicic acid in natural waters.
The mechanism of formation of diatoms has been studied and replicated for
microelectronics and various materials engineering applications. Inspired by the complex
shapes as well as the surface texturing of diatom skeletons, the Technical Objective of the
project delineated herein was to produce both porous and non-porous films of SiO2, with
surface texturing, deposited on various substrates in an endeavor to provide an inorganic tie-
coat between a metal substrate and a paint top-coat. The Business Objective of the project is
to replace various toxic coating processes currently found in manufacturing where products
of steel construction are utilized.
M 14
PULSED POWER GENERATION USING THE RELEASED HEAT OF
NANO-ENGINEERED THERMITES Maruf Hossain and Shubhra Gangopadhyay
Department of Electrical and Computer Engineering, University of Missouri, Columbia,
Missouri 65211 Email: [email protected]
Unconventional energy generation is becoming more important due to disappearing
natural resources and an increased concern for cleaning the environment. Direct energy conversion techniques that convert thermal and/or mechanical energy into electricity without the need for an intermediate fluid (as in the case of Rankine cycle based generators) are ideally suited for such remote applications. Thermoelectric power generators are direct energy conversion technologies that are attracting significant attention due to enhanced material properties and their ability to be scaled to very small dimensions.
Electricity can be generated if one junction of two electrically dissimilar materials is heated and the other junction is cooled (each junction is called a thermocouple). The performance of such a thermoelectric generator can be characterized by the maximum energy conversion efficiency, and is known to be dependent on the thermocouple material properties and the hot and cold temperatures.
To demonstrate this, we fabricated a device, where a clean glass substrate was coated with sputtered platinum film and a dispersed thermite (CuO nanorods/nano-Al). A schematic of this device is shown in figure 1. Two Pt-Al junctions were formed by soldering Al wire on the Pt films. An impact initiation was utilized to trigger a thermite reaction which produced heat in one junction. Due to a temperature differential, between two junctions, a voltage was generated, which was recorded using a data acquisition card (DAQ) and LabVIEW program. A voltage pulse of about 0.3 V peak and 126 microsecond width at FWHM was generated using one platinum strip (Figure 2). From the generated voltage value, the Seebeck coefficient of platinum is calculated to be approximately 17 µV/°C. In the present research, large temperature differential was used unlike the small temperature differential [1, 2] used by existing thermoelectric power generators.
0 200 400 600 800 1000-0.05
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0.05
0.10
0.15
0.20
0.25
0.30
0.35
Voltage generated by seebeck effect
Volta
ge (V
)
Time (µS)
Voltage output
Figure 1. Schematic of a device for thermo-
Thermites Platinum films
electric power generation using a thermite reaction. References: 1. Buist, Richard J.; Lau, Paul G., International Conferen1997. 2. Ichiro Matsubara, Ryoji Funahashi, Tomonari TakeucKazuo Ueno, Appl. Phys. Lett., vol. 78, p. 3627-3629, 200
Figure 2 Voltage generated using onePt strip.Figure Error! No text of specified
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n Thermoelectrics, Vol. 16, p. 551-554,
atoshi Sodeoka, Tadaaki Shimizu, and
M 15
LIGHT WAVEGUIDES WITH AN AQUEOUS CORE AND AN ULTRA
LOW REFRACTIVE INDEX NANOPOROUS SILICA CLADDING
Korampally Venumadhav, Manor Rosalynn, Othman Maslina, Kwon Jae and
Gangopadhyay Shubhra
Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri 65211
Email: [email protected] We present a novel chip based light waveguide system capable of guiding light
through aqueous solutions with minimal losses. The waveguide system comprises of an
aqueous core and an ultra low refractive index nanoporous silica cladding for efficient light
containment. The system comprises of channels etched in silicon and anodically bonded to
glass. These channels are later coated with nanoporous silica layer following our novel
coating method to form the cladding. The waveguide relies on total internal reflection within
the channels for light propogation. We have observed a tremendous increase in light
collection ability with our system compared to the control system with no nanoporous silica
coating.
M 16
MIC COMBUSTION WAVEFRONT VELOCITY IN ELASTOMERIC
MICROCHANNELS
Mike Kraus, Steve Apperson, Rajesh Shende, Raj Thiruvengadathan, Andrey
Bezmelnitsyn, Shubhra Gangopadhyay
Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri 65211
Email: [email protected]
Metastable intermolecular composites (MIC) are a novel form of energetic material.
Our MIC material is synthesized using a combination of CuO nanorods, and Al
nanoparticles. The Combustion wave velocity of this material has been observed to range
from 2000-2400 m/s. Experiments of the combustion wave velocity within confined
structures are reported here. The structures are of 15 x 1 mm x 225 µm (L:W:H)
microchannels fabricated from an elastomeric polymer, polydimethyl siloxane (PDMS). The
material is ignited using patterned heaters fabricated from a thin film of sputtered platinum.
The microchannels are cured The burn rate velocities of the material are presented as
measured in PDMS channels of varying rigidity
M 17
GROWTH AND CHARACTERIZATION OF NANOSIZE CO- DOPED
ZNO DILUTE MAGNETIC SEMICONDUCTORS S. Manchiraju, S. Pulugam, G. Mundada, R. K. Gupta, P. Kahol, and K. Ghosh
Department of Physics, Astronomy, and Materials Science, Missouri State University,
Springfield, Missouri-65897
Email: [email protected]
Dilute magnetic semiconductors (DMS) based on zinc oxide (ZnO) and transition
metals have attracted considerable attention due to their application in spintronic devices,
electro-optic switches, and memory for high speed computation. In this presentation we are
reporting electro-magnetic properties of ZnCoO nanostructured films grown by pulsed laser
deposition (PLD). The PLD target has been prepared by standard solid state reaction method.
X-ray diffraction and Raman spectroscopy measurements on films that were grown at
different temperatures indicate an orientation growth along the c-axis. The temperature
dependence of electrical resistivity of these films has been carried out in the temperature
range of 10 K to 300 K. It is observed that the resistivity decreases with an increase of
temperature, indicating the typical semiconducting behavior of these films. The Hall
measurement of these films has been carried out at room temperature. Different parameters
such as type of majority carriers, carrier concentration and mobility of the films grown at
different temperature have been calculated. It has been observed that the growth temperature
affect the carrier concentration and mobility of the material.
M 18
SPECTROSCOPIC ELLIPSOMETRY ANALYSIS OF NANOPOROUS
LOW DIELECTRIC CONSTANT FILMS PROCESSED VIA
SUPERCRITICAL CO2 FOR NEXT-GENERATION
MICROELECTRONIC DEVICES
Othman Maslina Tasrin and Shubhra Gangopadhyay
Electrical Engineering, University of Missouri, Columbia, Missouri 65211
Email: [email protected]
This research will address issues at the back-end-of-line in microelectronics
fabrication, specifically the need for Low-k extendibility. The International Roadmap for
Semiconductors (2005) suggested that interconnect insulation must be replaced with a
material having an ultra-low dielectric constant (k) of < 2.0 and can withstand rigorous
current process integration for the 65 nm technology. Creating porosity in the films produces
k-values as low (1.0) air. In this research, supercritical CO (SCCO ) process is utilized to
create pores, remove water, repair plasma-damaged sample and seal pores. These multi-step
processing does not only produce low-k film but also create device reliability. S
2 2
pectroscopy
ellipsometric (SE) analysis is used to evaluate the performance of each process on porous
film. In SE analysis, Cauchy, Bruggeman Effective Medium Approximation and graded
models are used to model the processed samples. The depth profile SE analysis demonstrates
the individual process performance based on its changes of refractive index (n) throughout
the film thickness. SE also provide important film properties like thickness, porosity etc. In
addition to SE, Fourier Transform Infra-red (FT-IR), Scanning Electron Microscopy (SEM)
and electrical characterizations are used. Results show that SCCO2/co-solvents can extract
porogens and remove water effectively at a significantly shorter time (≤1 hr) and at a low
temperature (≤160°C) without thickness shrinkage in contrast with thermal annealing which
uses 450°C and 5 hours without significantly shrinkage. SCCO2/TMCS removes water and
terminates silanol group with methyl group, and hence preventing water re-adsorption which
increases k. The dense layer on the sample surface that formed through the vapor
treatment/HMDS helps to seal pores and prevent metal diffusion.
M 19
NANOCOMPOSITE DIELECTRICS FOR QUANTUM DEVICES
Ravindran Ramasamy and Shubhra Gangopadhyay
Electrical Engineering, University of Missouri, Columbia, Missouri 65211
Email: [email protected]
Noble metal nanoparticles (nps) have been incorporated into oxide dielectric thin-
films. A doubling in dielectric constant (k) was noted for samples of Al2O3 and HfO2 relative
to a control sample. This enhancement is suggested to be the result of dipole and space
charge polarization mechanisms acting on the nps. Because of the resonant frequency of the
np dipoles and space-charge polarization, k enhancement was more prominent at lower
frequencies around 1 kHz compared with higher frequencies up to 1 MHz. We also discuss
applications of these nanocomposite thin-films in field effect transistors and floating gate
memory devices.
M 20
WRAP-AROUND-GATE SILICON NANOWIRE NMOS INVERTER
WITH LOW POWER CONSUMPTION AND ENHANCED SPEED
A. Seyedi, Justin Wilson, A. A. Pavel, Phumin Kirawanich, and N. E. Islam
Department of Electrical and Computer Engineering, University of Missouri-Columbia
Columbia, Missouri 65211, USA
Email: [email protected]
In the defense sector there is an urgent need for miniaturization of critical components of a weapon system that would benefit from advances of reduced size and weight integration. Systems include sensors, data transmission, computers and other microprocessor-driven devices, displays, global positioning system devices, etc. The silicon MOSFET, the workhorse of the semiconductor industry, is an integral part of many of the critical systems. A scaled down version of the device in Si technology would increase the packaging density of the chips employed in all the applications and could contribute greatly in fulfilling the needs. Scaling of silicon MOSFET dimensions is facing several challenges set by the limits of optical lithography and short channel effect (SCE). The classical single gate MOSFET has almost reached its minimum channel length limit imposed by gate oxide tunneling. Several non-classical models have been proposed to extend the scalability of MOS devices by reducing the SCE, including double gate [1], Pi-gate [2], and cylindrical surrounding or wrap around gate MOSFET [3, 4]. True scaling, however, can be realized only when there is a reduction of not only the channel length but the overall size of transistors. Because of the advantages in its integration with existing technology, Silicon (Si) MOSFET with nano scale channel and wrap-around-gate (WAG) has become a subject of active research. The WAG MOSFETs have been shown to have the best control over SCE and significantly improved carrier transport properties over conventional devices because of reduced scattering and better gate control [5]. Significant improvement of current density has been reported in nano-channel WAG devices as compared to its planer gate counterpart. We report on the fabrication and analysis of a silicon nano-channel WAG MOSFET. The SOI MOS device with 50 nm channel diameter is shown in Figure 1. It was fabricated using interferometric lithography in combination with conventional I line lithography. The experimental characteristics of the device and planar MOSFETs were compared with theoretical simulation results based on semi-empirical carrier mobility models. Enhancement of current density in the device can be attributed to higher longitudinal mobility achieved through the suppression of transverse electric field [4]. The right hand side of the figure shows the associated schematic diagram of the n-channel Si WAG MOSFET used in simulations with a diameter of 50 nm, a length of 2 microns. The plots in Figure 2 represent the I-V characteristic curves of the device, showing that drain current increases as the gate voltage moves toward positive value. We further analyze the device and presents mechanisms to further increase the channel current density and show the characteristics of a nano-scale inverter based on this WAG MOSFET. The inverter with WAG MOSFETs has been found to be superior to inverters with planar MOSFETs in terms of reduced power
M 21
consumption and rise time. Figure 3 presents the input-output characteristic of the inverters designed with WAG and planner MOSFETs. It clearly demonstrates the advantages of the nano inverter with smaller transition width (TW) and lower
Figure 1 SEM pictures of a slab gate and nanowire gate structures (left) and the three
dimensional view of the nchannel nanowire MOSFET (right).
Figure 2 Variation of drain current with drain tosource voltage as a function of gate voltage.
Figure 3 I/O Characteristics of planar and nanowireinverters comparing transition widths. Inset shows thenMOS inverter circuit.
switching voltage. The WAG inverter simulation setup and results, such as the power consumption and the transient response of planar MOS inverter and nanowire MOS inverter will be detailed in the full version of the paper, including influences on such parameters due to the channel length and diameter. References 1. Y. Taur, “An Analytical Solution to a Double-Gate MOSFET with Undoped Body,” IEEE Electron Device Lett., vol. 20. no. 5, pp. 245-247, May 2000. 2. J.-T. Park, J. P. Collinge and C. H. Diaz, “Pi-gate SOI MOSFET,” IEEE Electron Device Lett., vol. 22, no 8, pp. 405-406, August 2001. 3. D. Jiménez, B. Iñíguez, J. Suñé, L. F. Marsal, J. Pallarès, J. Roig, and D. Flores, “Continuous Analytic I–V Model for Surrounding-Gate MOSFETs,” IEEE Electron Device Lett., vol. 25, no. 8, August 2004 4. A. K. Sharma, S. H. Zaidi, S. Lucero, S. R. J. Brueck, and N. E. Islam, “Mobility and transverse electric field effects in channel conduction of wrap-around-gate nanowire MOSFETs,” IEE Proceedings - Circuits, Devices and Systems, volume 151, issue 5, p. 422-430, October 2004. 5. E. Leobandung, G. Gian, G. Lingjie, and S. Y. Chao, “Wire-channel and wrap-around-gate metal-oxide semiconductor field-effect transistors with a significant reduction of short channel effects,” J. Vac. Sci. Technol. B, 5, (6), p. 2791, 1997.
M 22
SELF ASSEMBLY OF OXIDE NANO-STRUCTURES USING PULSED
LASER DEPOSITION
Matthew W. Summers, Ram Gupta, Pawan Kahol, Kandiah Manivannan, and Kartik
Ghosh
Department of Physics, Astronomy, and Materials Science, Missouri State University,
Springfield, Missouri
Email: [email protected]
Nano-structured materials are responsible for many technological advances in nearly
every discipline of physical science. This paper is concerned with the self-assembly of
nanostructure in Titania (TiO2) thin films grown using pulsed laser deposition with
applications in photovoltaic devices, photochemical catalysis, and high power electronics.
We have observed self-assembly of TiO2 into pyramids with a relatively high degree of
uniformity and morphology that is dependent on the thickness of the deposition. Our
observations include discrete clustering of nano-structures as thickness is increased. We
have utilized atomic force microscopy for imaging the thin films, and the Mathworks Matlab
software package for the statistical analysis of surface morphology. TiO2 is a wide band gap
semiconductor in bulk form, and we are interested in characterizing the band gap as a
function of changes in feature size. Our overall goal is to understand the dependence of the
band gap on film thickness and surface morphology. We are performing photoluminescence
spectroscopy to accomplish this. We will present preliminary results of AFM imaging,
surface morphology analysis, and band gap characterization.
M 23
COPPER CHLORIDE BASED SOL-GEL SYNTHESIS OF COPPER
OXIDE FOR USE IN NANO-ENERGETIC MATERIALS.
Daniel Tappmeyer, Shubhra Gangopadhyay, Rajesh Shende, Keshab Gangopadhay, Steve Apperson, Rajagopalan Thiruvengadathan
Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri 65211
Email: [email protected]
Due to growing interest in Copper Oxide based Energetic Materials, a more cost effective method of preparing Copper Oxide for use in Energetic Materials was sought. Previous methods of preparing Copper Oxide for use in Energetic Materials have relied on Copper Ethoxide as the primary precursor. Materials prepared by this method have been demonstrated to have extremely good energetic properties with burn rates in excess of 2000 m/s. However, despite the very good energetic properties of the material produced by this method of synthesis the extremely high cost of Copper Ethoxide (~ $675/ 100g Copper Ethoxide) has limited the practical applications of material prepared by this method. Therefore a new method preparing Copper Oxide utilizing a less expensive precursor material was sought. Experimentation has revealed Copper Oxide can be formed using a sol-gel method which utilizes Copper(II) Chloride as the primary precursor. The relatively affordable cost of Copper(II) Chloride (~ $9.60/ 100g Copper(II) Chloride) makes this method an attractive alternative to Copper Ethoxide preparation. FTIR of Copper Oxide prepared by the Copper(II) Chloride method has shown that extremely pure Copper Oxide can be prepared by this method of synthesis. Because this method utilizes a sol-gel process it is believed surfactant templating can be used in the preparation of Copper Oxide to increase the porosity of the resulting material, leading to better energetic properties. Several samples were prepared utilizing various concentrations P-123 surfactant. Burn rate measurement of the resulting Copper Oxide, combined with aluminum nano-particle fuel has been shown to produce burn rates in excess of 1300 m/s. This burn-rate far exceeds the expected burn-rate of ~700 m/s for typical Copper Oxide nano-particles. This seems to indicate the surfactant templating method was successful in increasing the porosity of the resulting Copper Oxide. However, TEM was unable to confirm the formation of porous structures. Although Copper Oxide prepared by the Copper(II) Chloride method of preparation currently performs at a level below similar material prepared by the Copper Ethoxide method, early results have shown Copper Oxide prepared by the Copper(II) Chloride method is suitable for energetic purposes. It is hoped that with further refinement Copper Oxide prepared by the Copper(II) Chloride method will be able to perform on a level comparable to materials prepared by the current Copper Ethoxide method at a much more affordable cost.
M 24
SYNTHESIS AND CHARACTERIZATION OF COPPER OXIDE
BASED NANOENERGETIC COMPOSITES
Rajagopalan Thiruvengadathan, Rajesh V. Shende, Paul Koch, Steven Apperson,
Andrey V. Bezmelnitsyn and Shubhra Gangopadhyay
Department of Electrical and Computer Engineering, University of Missouri, Columbia, MO
65211.
Email: [email protected]
In order to realize high combustion rates, it is essential to enhance the interfacial
contact between oxidizer copper oxide (CuO) nanorods and fuel Aluminum (Al)
nanoparticles. Enhanced interfacial contacts will ensure faster thermite reactions. We show
that self-assembly processes can facilitate homogeneous distribution of fuel nanoparticles
around the oxidizer, thereby leading to enhanced interfacial contacts.
Copper oxide nanorods were synthesized by inorganic condensation method using
polyethylene glycol (PEG) surfactant as a template. The structural properties of CuO
nanorods were determined using X-ray diffraction, transmission electron microscopy and
Fourier transform infrared spectroscopy. Al nanoparticles were assembled around CuO
nanorods employing poly (4-vinylpyridine) (P4VP). The pyridyl group in this polymer
provides the binding sites to enable assembling of the Al nanoparticles around the oxidizer
nanorods. The energetic performance of such self-assembled composite is superior in
comparison with that of a composite prepared without self-assembly. Our results reveal that
the combustion speeds of self-assembled composite is 2100 ± 100 m/s.
M 25
FIELD-EFFECT TRANSISTORS BASED ON SINGLE NANOWIRES
OF CONDUCTING POLYMERS
Adam K. Wanekaya,* Mangesh A. Bangar,# Minhee Yun+, Wilfred Chen,#
Nosang V. Myung# and Ashok Mulchandani#
Chemistry Department, Missouri State University, Springfield MO 65897 #Department of Chemical and Environmental Engineering and Center for Nanoscale Science
and Engineering, University of California, Riverside, CA, 92521 + Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh,
PA 15261.
Email: [email protected]
We report the electronic characteristics of field-effect transistors based on single
conducting polymer nanowires. The 100 nm-wide and 2.5 micron-long conducting polymer
nanowire field-effect transistors were turned “on” and “off” by electrical or chemical signals.
A large modulation in the electrical conductivity of up to three orders of magnitude was
demonstrated as a result of varying the electrochemical gate potential of these nanowires.
Single conducting polymer nanowire field-effect transistors show higher electrical
performance than field-effect transistors based on conducting polymer nanowire electrode
junctions and thin films in terms of their transconductance (gm) and on/off current (Ion/Ioff)
ratio. Furthermore, the performance of the single conducting nanowire field-effect
transistors was found to be comparable to the silicon nanowire field-effect transistors. These
results imply that it is possible to tune the sensitivities of these conducting polymer
nanowires by simple control of the electrolyte/liquid ion gate potentials. Based on these
findings, we demonstrated the ability to tailor the sensitivities of sensors based on single
conducting polymer nanowires.
M 26
LATTICE FRINGE SIGNATURES OF EPITAXY ON NANOTUBES Jinfeng Wang and P. Fraundorf
Physics and Astronomy and Center for Molecular Electronics, University of Missouri-St.Louis (63121), St.Louis, MO, USA
Email: [email protected] Carbon nanotubes are of increasing interest for nanotechnology applications in general [1, 2]. They are also interest as supports for heterogeneous catalysts [3], for example in fuel cell applications. Carbon nanotubes also have advantages for electron microscopy, because their near-cylindrical symmetry and propensity of lie perpendicular to the electron beam makes data acquisition and interpretation much simpler than for single crystal supports. We show here that, with help from recent work on the theory of lattice fringe visibility, that the crystallographic relationship between catalyst nanocrystals and their nanotube supports (Fig.1) can sometimes be inferred from a single lattice fringe image. If the relationship is epitaxial, one might conversely decorate tubes in order to determine the chirality of their outer sheet. We illustrate this with a specific case: Growth of FCC metals on (0002) graphite surfaces and/or grapheme sheets. The theory is easily extended to growth of other lattice types. Application to experimental images of Pt fuel cell catalyst crystals, on carbon nanotube supports, illustrates the strategy. According to diffraction data in the literature, epitaxy of FCC Pd on single crystal graphite (0002) planes typically takes place with parallel to in the growth direction, and parallel to in the plane of the substrate. This fully specifies the expected fringe distributions.
Pd)111( graphite)0002(
Pd]112[ graphene]0.01[
The bottom up view of such a 65 Pd-atom nanocrystal on grapheme is shown in Fig. 4. Here for simplicity we have approximately positioned two of every three bottom-layer Pd atoms directly over a carbon atom, with the result that one of every three is over the center of a cyclohex graphene ring. The actual transitional alignment of the nanoparticle should have little effect on metal fringe visibility, provided that contrast from the underlying carbon does not obscure the metal lattice. Because the Pd lattice azimuth is now fixed with respect to top graphene sheet of the underlying nanotube, the fringe visible will be fully specified by the projected position for a given top sheet chirality. The result is illustrated at the bottom of Fig. 5 for armchair, zigzag, and “15 degree” chiral top-layer orientations, in sequence. As a fringe benefit, epitaxial “decoration” of carbon nanotubes will in principle make routine determination of top-layer tube chirality. Of course, prepartation of nanotube surfaces sufficiently clean and flat for epitaxial decoration may not be trivial. Reference [1] M.S.Dresselhaus et al., Science of Fullerenes and Carbon Nanotubes, Academic Press, New York, 1996. [2] H. Dai, Surface Science 500,218 (2002). [3] P. N. Rylander, Catalytic Hydrogenation in Organic Synthesis, Academic Press, New York, London, 1979.
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PLASMA NANOCOATED DIAMOND NANOPARTICLES FOR HEAT
TRANSFER NANOFLUIDS Q.S. Yu,1 Y. J. Kim,1 C. Wilson,2 K. Park,2 H.B. Ma 2
1 Center for Surface Science and Plasma Technology, Department of Chemical
Engineering, University of Missouri-Columbia, Columbia, MO65211 2 Department of Mechanical and Aerospace Engineering, University of Missouri-
Columbia, Columbia, MO65211
Email: [email protected], Email: [email protected]
Effective thermal management has become one of the most serious challenges in many new
technologies due to constant demands for high computing speeds and continuous reduction of
device dimensions. Ultrahigh thermal conductivity of nanofluids produced by adding only a
small amount of nanoparticles into heat transfer fluids has qualified nanofluids as the most
promising candidates for achieving ultra-high-performance cooling, a crucial factor for next
generation computer chip development and cryopreservation of cells for biological
researches. In this study, low-temperature plasma nanocoatings were used to modify
diamond nanoparticles and tailor their surface characteristics in order to improve their
dispersion capability in water and thus enhance the thermal conductivity of the resulted
nanofluids. It was found that the plasma treatment significantly reduced water contact angle
of diamond nanoparticles and thus rendered the nanoparticles with strong water affinity for
dispersion enhancement in polar media such as water. Surface analysis using Fourier
Transform Infrared (FTIR) confirmed that polar groups were imparted on nanoparticle
surfaces. As a result, improved suspension stability and increased thermal conductivity was
observed with plasma treated nanoparticles dispersed in water.
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ELECTRICAL CHARACTERIZATION OF POLYFLUORENE-BASED
METAL-INSULATOR-SEMICONDUCTOR DIODES
M. Yun1, M. Arif2, S. Gangopadhyay1 and S. Guha2
Department of Electrical and Computer Engineering1, Department of Physics and
Astronomy2, University of Missouri, Columbia, MO 65201 USA
Email: [email protected]
Polyfluorenes (PFs) have emerged as a promising family of blue polymer light-emitting
diodes (PLEDs) due to their high electroluminescence quantum yield. Despite the rapid
progress in PF-based PLEDs these devices have lower carrier mobility compared with
evaporated organic molecules. Additional issues such as interface states can considerably
affect the electrical properties of such devices.
We present investigation of electrical characterization of the ethyl-hexyl substituted
polyfluorene (PF2/6) using the hybrid metal-insulator-semiconductor structure based on
conjugated polymer, PF2/6 as the active semiconductor which was fabricated on p+-Si
substrate with Al2O3 as the insulator. Through the capacitance-voltage (C-V) and
conductance-voltage techniques, the presence of distribution of trap charges at the
Al2O3/(PF2/6) interface is observed. The negative shift of the flat-band voltage with
increasing frequency arises from positive interface charges into the Al2O3/(PF2/6) layer.
From the C-V measurements localized doping density is evaluated as ~5.7×1017 cm-3 at
frequencies above 20 kHz. The interface trap density is estimated as ~7.7×1011 eV-1cm-2 at
the flat-band voltage. PF2/6 films will be suitable polymer semiconductor to develop high
performance thin-film transistors for polymer electronics and biological sensors such as
medical diagnostics and detection of chemicals due to their small volume, portability, and
inexpensiveness.
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PORE STRUCTURE IN ACTIVATED CARBON WITH
APPLICATIONS TO METHANE STORAGE
Mikael Wood, Jacob Burress, Peter Pfeifer
Department of Physics and Astronomy, University of Missouri-Columbia
Parag Shah, Galen Suppes, Department of Chemical Engineering, University of Missouri-Columbia
Email: [email protected]
As a part of the Alliance for Collaborative Research in Alternative Fuel Technology
(ALL-CRAFT) our group studies the formation and properties of nanoscale pore structures in
activated carbon with the goal of storing methane at low pressures. To study the pore
structure of activated carbon we employ various methods including small/ultra-small angle x-
ray scattering (SAXS/USAXS), methane and nitrogen adsorption isotherms, electron
microscopy, and cellular automata modeling. By assuming a two phase model with
uncorrelated spherical pores we show that the pore size distribution (PSD) obtained from
methane and nitrogen adsorption is in excellent agreement with SAXS/USAXS data. We also
show that data obtained from probabilistic cellular automata modeling of the pore formation
process yields data that is consistent with both SAXS/USAXS and methane and nitrogen
adsorption. Finally, we show that many of our carbon samples have desirable properties for
methane storage.
Project supported by: National Science Foundation (EEC-0438469), University of
Missouri, Midwest Research Institute, Argonne National Laboratory, U.S. Department of
Education (GAANN), and U.S. Department of Energy (W-31-109-Eng-38)
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COHERENCE EFFECTS IN ELECTRON DIFFRACTION FROM
PRESOLAR GRAPHENES E. Mandell, P. Fraundorf
Department of Physics and Astronomy and Center for Molecular Electronics University of Missouri – St. Louis, St. Louis, Missouri 63121
This set of analyses examines how coherence effects for coordinated atom-thick structures evidence themselves in diffraction. It also provides an example where this effect may be occurring in nature, through the examination of carbonaceous materials condensed from meteorites. For atom-thick structures, these coherence effects may be seen in diffraction, and they provide additional structural information beyond simple lattice periodicities [1]. The target here is unlayered graphene in the core of a subset of the isotopically heavy (i.e. with 12C/13C < solar=89), micron-sized, ultramicrotomed graphite spherules from the Murchison meteorite (Fig. 1) [2]. These presolar particles are characterized by “graphite onion” rims (with a concentric arrangement of 0.34[nm] (002) graphite layers) surrounding the spherical cores of interest. The core is comprised primarily of atom-thick graphene “flakes” [3, 4], as shown e.g. by the presence of graphite (hk0) ordering in electron diffraction, with no sign of the 0.34[nm] (002) graphitic layering characteristic of graphite, amorphous carbon, multi-wall carbon nanotubes, and most solid non-diamond carbon phases (Fig. 1). While flat-sheet diffraction models for graphene sheets fit experimental data from the cores reasonably well, systematic differences arise. For example, we have applied Warren models [5] for single-sized flat sheets, two sheet sizes, and a log-normal size distribution of flat sheet sizes to fit the experimental data. Each of these left the extra scattering at the graphene peaks and on the leading (low-frequency) edge unresolved. Also, the same residual effects were seen in experimental diffraction patterns from different spherules. One explanation for these differences is the coherence effect that results from coordination between adjacent graphene sheets. Fig. 2 contains a model faceted nanocone and the three dimensional reciprocal lattice structure corresponding to the (110) lattice spacing for each sheet. Of interest are the intersections of the harmonics, where the triple intersections serve to slightly broaden or shift the location of the (110) peak, and where the double intersections (where two rel-rods nearly touch) result in a satellite peak. For clarity, Fig. 3 shows a modeled azimuthally-averaged diffraction profile for two adjacent facets and a single facet, or flat sheet. If the angle between the facets is changed, these coherence spikes will also move, as the preferential foreshortening of the molecule is altered, or the intersections of corresponding rel-rods in reciprocal space occur at different spatial frequencies. Using a least squares, splined, fitting routine that uses Debye diffraction models for flat sheets, we compare the systematic differences that arise when fitting experimental data to those calculated for assemblages of randomly-oriented graphene, or faceted structures (Fig. 4) [6]. Visually, we see the similar inability of the flat sheet model to fit the amount of scattering at the (100) and (110) peaks in both the experimental data and the model ensemble of randomly-oriented graphene. The flat-sheet model also falls short on the leading edge of the graphene spacings in both cases. Thus, the inability of the flat sheet model to fit core electron diffraction may be due to coherence effects arising from inter-sheet relationships.
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References: 1. J. M. Cowley, Acta. Cryst. 14, 920 (1961) 2. S. Amari, E. Zinner, and R.S. Lewis, Meteoritics 30, 679 (1995). 3. T. Bernatowicz, et. al., Astrophysical Journal 472, 760 (1996). 4. P. Fraundorf and M. Wackenhut, Ap. J. Lett. 578, L153 (2002). 5. B.E. Warren, Phys. Rev 59(9), 693 (1941). 6. B.E. Warren, X-Ray Diffraction, Addison-Wesley/Dover, New York (1969/1990).
Figure 1: A presolar graphite spherule with a Figure 2: A picture of atom positions for a faceted core-rim structure, and a diffraction pattern carbon nanocone consisting of five flat faces, and from the core. The (002) graphite spacing is the corresponding reciprocal lattice structure for absent in diffraction. (110) periodicity.
Figure 3: A comparison of Debye diffraction patterns for one and two facets of the faceted nanocone. Observe the occurrence of a satellite peak due to the orientation of the facets.
Figure 4: Debye flat sheet models fitted to experimental data and an ensemble of randomly-oriented flat sheets. Similarities in differences may arise, simply from coherence
M 32
PULSED POWER GENERATION USING THE RELEASED HEAT OF
NANO-ENGINEERED THERMITES 1Maruf Hossain and 1,2Shubhra Gangopadhyay
1Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri 65211
Email: [email protected] Unconventional energy generation is becoming more important due to disappearing
natural resources and an increased concern for cleaning the environment. Direct energy conversion techniques that convert thermal and/or mechanical energy into electricity without the need for an intermediate fluid (as in the case of Rankine cycle based generators) are ideally suited for such remote applications. Thermoelectric power generators are direct energy conversion technologies that are attracting significant attention due to enhanced material properties and their ability to be scaled to very small dimensions.
Electricity can be generated if one junction of two electrically dissimilar materials is heated and the other junction is cooled (each junction is called a thermocouple). The performance of such a thermoelectric generator can be characterized by the maximum energy conversion efficiency, and is known to be dependent on the thermocouple material properties and the hot and cold temperatures.
To demonstrate this, we fabricated a device, where a clean glass substrate was coated with sputtered platinum film and a dispersed thermite (CuO nanorods/nano-Al). A schematic of this device is shown in figure 1. Two Pt-Al junctions were formed by soldering Al wire on the Pt films. An impact initiation was utilized to trigger a thermite reaction which produced heat in one junction. Due to a temperature differential, between two junctions, a voltage was generated, which was recorded using a data acquisition card (DAQ) and LabVIEW program. A voltage pulse of about 0.3 V peak and 126 microsecond width at FWHM was generated using one platinum strip (Figure 2). From the generated voltage value, the Seebeck coefficient of platinum is calculated to be approximately 17 µV/°C. In the present research, large temperature differential was used unlike the small temperature differential [1, 2] used by existing thermoelectric power generators.
Figure 1. Schematic of a device for thermoelectric
0 200 400 600 800 1000-0.05
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
Voltage generated by seebeck effect
Volta
ge (V
)
Thermites Platinum films
Voltage output
power generation using a thermite reaction. References: [1] Buist, Richard J.; Lau, Paul G., International Con
554, 1997. [2] Ichiro Matsubara, Ryoji Funahashi, Tomonari T
and Kazuo Ueno, Appl. Phys. Lett., vol. 78, p. 36
Time (µS)
Figure 2) Voltage generated using onPt strip.
ference on Thermoelectrics, Vol. 16, p. 551-
akeuchi, Satoshi Sodeoka, Tadaaki Shimizu, 27-3629, 2001.
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