Nanoscale Biosensors Based on Luminescent Quantum Dots · 2014-01-30 · Nanoscale Biosensors Based...
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Nanoscale Biosensors Based on Luminescent Quantum Dots Hedi Mattoussi and Ellen R. Goldman Optical Sciences Division and Center for Bio/Molecular Science and Engineering (CBMSE) To develop QD multianalyte biosensors Sensors capable of long-term environmental monitoring Objectives QD Q E xc A analyte hν Prototype Concept QD Q E xc quencher FRET Add analyte Regenerate Unexploded Ordnance Detection: Continuous monitoring for underwater detection of explosives Biological Screening of Toxins (Force Protection): Sensing systems for monitoring of drugs, toxins, pathogens, and environmental contaminants Payoffs Different color QDs Design and implement new syntheses of highly luminescent QDs Utilize QDs with bioreceptors to assemble multi- analyte biosensors for long-term environmental monitoring Assembly of biomolecular receptors onto luminescent QDs Control FRET between a QD and dye-labeled receptor upon interaction with target analyte Approaches P = O: P: Caps: TOP TOPO • Synthesis of CdSe QDs: Murray et al., J. Am. Chem. Soc. 115, 8706 (1993) • Synthesis of CdSe-ZnS QDs: (1) Hines et al., J. Phys. Chem. 100, 468 (1996) (2) Dabbousi et al., J. Phys. Chem. B 101, 9463 (1997) Unique features of Quantum Dot fluorophores UV source at λ≅ 365 nm R = 12Å 14Å 18Å 22Å 25Å 30Å (Dabbousi et al., J. Phys. Chem. B 101, 9463 (1997)) organic caps ZnS shell 4eV 2eV CdSe core R 0 ~10-60Å Tunable photoemission: Maintain the same composition but vary the size across the range of accessible wavelengths size choice of group II or VI elements Binary CdSe QDs Wavelength (nm) 450 500 550 600 650 Size: R (Å) Photoluminescence varies with QD size 12 20 40 Homogeneous core formation Tunable photoemission: Maintain uniform size across wide wavelength domain % composition choice of group II or VI elements size Design of Alloyed QDs Wavelength (nm) 300 400 500 600 700 800 900 CdSe CdSe x Te 1-x Zn x Cd 1-x Se Composition Photoluminescence domain varies for a fixed QD size 4. FRET-based sensor concept d y e 5 - his QD Excitation QD emission • FRET Involves the non- radiative exciton transfer from a donor to an acceptor • Transfer efficiency varies as ~ (1 / r 6 ) • Proximity driven • It is a powerful sensing tool, used to detect binding events • Requires spectral (or energy) overlap QD emission FRET Dye emission Design of QD nanoscale TNT sensor based on Fluorescence Resonance Energy Transfer (FRET) 475 500 525 550 575 600 625 650 675 700 0 5e+5 1e+6 2e+6 2e+6 3e+6 3e+6 0:1 MBP-Cy3/QD 1:1 MBP-Cy3/QD 2:1 MBP-Cy3/QD 3:1 MBP-Cy3/QD 4:1 MBP-Cy3/QD 5:1 MBP-Cy3/QD 7:1 MBP-Cy3/QD 10:1 MBP-Cy3/QD 0 2 4 6 8 10 0.0 0.2 0.4 0.6 0.8 1.0 555 QDs MBP-Cy3 E (QD PL quenching) λ (nm) PL (a.u.) Relative PL; efficiency ratio MBP-Cy3/QD 555 nm emitting QDs titrated with MBP-Cy3 Integrated PL vs. acceptor ratio 7 System predisposed for multiplexing (multiple analytes can be targeted simultaneously) QD Cy3 MBP QD Cy3 MBP • J(λ) = 8.91×10 -13 cm 3 /M => R 0 = 58.6 Å • Tunable QD excitation => Choose a minimum for the dye I. Medintz et al., Nature Materials 2, 630 (2003) and A. Clapp et al., J. Am. Chem. Soc., In press 2. Advantages of QDs in FRET 5. TNT monitoring system Recognition elements: withstand nonstandard matrixes (seawater) Robust reporters: photo- and chemically stable QDs Easily identifiable: ‘On’ or ‘Off’ luminescence 3. Illustration of energy transfer : Time-resolved fluorescence t = 0.5 ns t = 2.5 ns t = 4.5 ns t = 6.5 ns QD/10MBP QD/3MBP- Cy3 Cy3 only 510 570 510 570 510 570 510 570 1. FRET concept FRET Exc FRET Exc QD ‘On’ State: Strong luminescence QSY - 7 QD Exc TNT QD QD ‘On’ State: Strong luminescence QSY - 7 QSY - 7 QSY - 7 QD substrate Exc Exc TNT TNT Flexible Linker ‘Off’ State: No emission Antibody fragment TNT analog Quencher dye Q SY - 7 QD Flexible Linker ‘Off’ State: No emission Antibody fragment TNT analog Quencher dye Q SY - 7 Q SY - 7 Q SY - 7 substrate QD QD TIME SIGNAL: PL QD QD QD QD QD hν Q Analyte Analyte in recognition site. QD emits Exc hν QD QD QD QD QD QD QD QD QD QD hν Q Q Analyte Analyte in recognition site. QD emits Exc Exc hν Q Q Receptor No analyte No QD emission Exc Exc Analog-labeled quencher QD QD FRET FRET Exc Exc FRET FRET FRET FRET QD QD QD QD Q Q No analyte Baseline signal RESET Exc Exc Properties: • Robust, real time • Able to regenerate • Reset by flushing with buffer Maltose Concentration uM 10 -2 10 -1 10 0 10 1 10 2 10 3 Fluorescence at 600 nm 200 400 600 800 1000 1200 1400 k d ~ 55.2 Cy3.5 6 carbon spacer 15 carbon space Flexible hybridized DNA linker Biotin for attachment to NeutrAvidin β-cyclodextrin Cy3.5 6 carbon spacer 15 carbon space Flexible hybridized DNA linker Biotin for attachment to NeutrAvidin β-cyclodextrin Titration of P1-Cy3.5- B-CD on NeutrAvidin plate with MBP-95C- QSY7 added versus Maltose concentration MBP Q QSY7 NeutrAvidin Already constructed and tested: a prototype of a fixed-tether assay Substrate Flexible hybridized DNA linker FRET Biotin β-CD-Cy3.5 • Assay is based on competition displacement • Employs reverse quenching as the transduction signal Exc Add Maltose MBP Q QSY7 QSY9-MBP Displaced Direct Emission NeutrAvidin Substrate Flexible hybridized DNA linker Biotin β-CD-Cy3.5 Exc Tether structure Key research milestones Design and develop new QDs with broad emission wavelengths Develop QD-surface ligands for water-compatibility and covalent conjugation Optimization of QD-acceptor FRET spectral overlap and separation distances Sensor optimization by linker and donor-acceptor pairs Design and optimization of multireceptor QD-bioconjugates Develop sensors that target analytes of interest to the Navy – TNT – RDX – Toxins – Pathogens – Environmental contaminant Collaboration with: • Professor M.G. Bawendi and his group at MIT • Professor S. Simon and his group at Rockefeller University Funding from ONR, Keith Ward program Publications • 14 refereed publications, 1 patent, 9 proceedings, and 3 book chapters Work highlighted in Science, Nature Biotechnology, and Small Time magazine Seminal papers: • H. Mattoussi, J.M. Mauro, E.R. Goldman, G.P. Anderson, V.C. Sundar, F.V. Mikulec and M.G. Bawendi, J. Am. Chem. Soc. 122, 12142-12150 (2000). • E.R. Goldman, G.P. Anderson, P.T. Tran, H. Mattoussi, P.T. Charles, and J. M. Mauro, Analytical Chemistry 74, 841-847 (2002). • J.K. Jaiswal, H. Mattoussi, J.M. Mauro, and S.M. Simon, Nature Biotechnology 21, 47-51 (2003). • I.L. Medintz, A.R. Clapp, H. Mattoussi, E.R. Goldman, and J.M. Mauro, Nature Materials 2, 630-638 (2003). Acknowledgments:
Transcript of Nanoscale Biosensors Based on Luminescent Quantum Dots · 2014-01-30 · Nanoscale Biosensors Based...
Nanoscale Biosensors Based on Luminescent Quantum DotsHedi Mattoussi and Ellen R. Goldman
Optical Sciences Division and Center for Bio/Molecular Science and Engineering (CBMSE)
To develop QD multianalyte biosensors
Sensors capable of long-term environmental monitoring
Objectives
QD
Q
Exc
A
analyte
hνPrototype Concept
QD
Q
Exc
quencherFRET
Add analyte
Regenerate
Unexploded Ordnance Detection:Continuous monitoring for underwater detection of explosives
Biological Screening of Toxins (Force Protection):Sensing systems for monitoring of drugs, toxins, pathogens, and environmental contaminants
Payoffs
Different color QDs
Design and implement new syntheses of highly luminescent QDs
Utilize QDs with bioreceptors to assemble multi-analyte biosensors for long-term environmental monitoring
Assembly of biomolecular receptors onto luminescent QDs
Control FRET between a QD and dye-labeled receptor upon interaction with target analyte
Approaches
P=O:P:Caps:
TOP TOPO
• Synthesis of CdSe QDs: Murray et al., J. Am. Chem. Soc. 115, 8706 (1993) • Synthesis of CdSe-ZnS QDs: (1) Hines et al., J. Phys. Chem. 100, 468 (1996)
(2) Dabbousi et al., J. Phys. Chem. B 101, 9463 (1997)
Unique features of Quantum Dot fluorophores
UV source at λ ≅ 365 nm
R = 12Å 14Å 18Å 22Å 25Å 30Å
(Dabbousi et al., J. Phys. Chem. B 101, 9463 (1997))
organic capsZnS shell
4eV 2eV CdSe coreR0~10-60Å
Tunable photoemission:
Maintain the same composition but vary the size across the range of accessible wavelengths
sizechoice of group II or VI elements
Binary CdSe QDs
Wavelength (nm)450 500 550 600 650
Size
: R (Å
)
Photoluminescence varies with QD size
12
20
40
Homogeneous core formationTunable photoemission:
Maintain uniform size across wide wavelength domain
% compositionchoice of group II or VI elementssize
Design of Alloyed QDs
Wavelength (nm)300 400 500 600 700 800 900
CdSe
CdSexTe1-x
ZnxCd1-xSe
Composition
Photoluminescence domain varies for a fixed QD size
4. FRET-based sensor concept
dye
5-his
QDExcitation
QD emission
• FRET Involves the non-radiative exciton transfer from a donor to an acceptor
• Transfer efficiency varies as ~ (1 / r 6)
• Proximity driven
• It is a powerful sensing tool, used to detect binding events
• Requires spectral (or energy) overlap
QD emission
FRET
Dyeemission
Design of QD nanoscale TNT sensor based on Fluorescence Resonance Energy Transfer (FRET)
475 500 525 550 575 600 625 650 675 7000
5e+5
1e+6
2e+6
2e+6
3e+6
3e+6
0:1 MBP-Cy3/QD1:1 MBP-Cy3/QD2:1 MBP-Cy3/QD3:1 MBP-Cy3/QD4:1 MBP-Cy3/QD5:1 MBP-Cy3/QD7:1 MBP-Cy3/QD10:1 MBP-Cy3/QD
0 2 4 6 8 100.0
0.2
0.4
0.6
0.8
1.0
555 QDsMBP-Cy3E (QD PL quenching)
λ (nm)
PL (a
.u.)
Rel
ativ
e PL
; effi
cien
cy
ratio MBP-Cy3/QD
555 nm emitting QDs titrated with MBP-Cy3 Integrated PL vs. acceptor ratio
7
System predisposed for multiplexing (multiple analytes can be targeted simultaneously)
QD
Cy3MBP
QD
Cy3MBP
• J(λ) = 8.91×10-13 cm3/M => R0 = 58.6 Å
• Tunable QD excitation => Choose a minimum for the dye
I. Medintz et al., Nature Materials 2, 630 (2003) and A. Clapp et al., J. Am. Chem. Soc., In press
2. Advantages of QDs in FRET
5. TNT monitoring system
Recognition elements: withstand nonstandard matrixes (seawater)Robust reporters: photo- and chemically stable QDsEasily identifiable: ‘On’ or ‘Off’ luminescence
3. Illustration of energy transfer : Time-resolved fluorescence
t = 0.5 ns t = 2.5 ns t = 4.5 ns t = 6.5 ns
QD/10MBP
QD/3MBP-Cy3
Cy3 only
510 570 510 570 510 570 510 570
1. FRET concept
FRET
Exc
FRET
Exc
QD
‘On’ State: Strong luminescence
QSY-7
QD
substrate
Exc
TNT
QDQD
‘On’ State: Strong luminescence
QSY-7QSY-7QSY-7
QD
substratesubstrate
ExcExc
TNTTNT
FlexibleLinker
‘Off’ State: No emission
Antibodyfragment
TNT analog
Quencher dye
QSY-7
substrate
QD FlexibleLinker
‘Off’ State: No emission
Antibodyfragment
TNT analog
Quencher dye
QSY-7QSY-7QSY-7
substratesubstrate
QDQD
TIME
SIG
NA
L: P
L
QDQDQDQDQD hν
QAnalyte
Analyte in recognition site. QD emits
Exc
hν
QDQDQDQDQDQDQDQDQDQD hν
QQAnalyte
Analyte in recognition site. QD emits
ExcExc
hν
Receptor
No analyteNo QD emission
ExcExc
Analog-labeledquencher
QDQD
FRETFRET
ExcExc
FRETFRET FRETFRET
QDQDQDQD
No analyteBaseline signal
RESET
ExcExc
Properties: • Robust, real time • Able to regenerate • Reset by flushing with buffer
Maltose Concentration uM10-2 10-1 100 101 102 103
Fluo
resc
ence
at 6
00 n
m
200
400
600
800
1000
1200
1400
kd~ 55.2
Cy3.5
6 carbon spacer
15 carbon space
Flexible hybridized DNA linker
Biotin for attachment to NeutrAvidin β-cyclodextrin
Cy3.5
6 carbon spacer
15 carbon space
Flexible hybridized DNA linker
Biotin for attachment to NeutrAvidin β-cyclodextrin
Titration of P1-Cy3.5-B-CD on NeutrAvidin plate with MBP-95C-QSY7 added versus Maltose concentration
MBPQ
QSY7
NeutrAvidin
Already constructed and tested: a prototype of a fixed-tether assay
Substrate
Flexible hybridized DNA linker
FRET
Biotin
β-CD-Cy3.5
• Assay is based on competition displacement• Employs reverse quenching as the
transduction signal
Exc
Add Maltose MBPQ
QSY7
QSY9-MBP Displaced
Direct Emission
NeutrAvidin
Substrate
Flexible hybridized DNA linker
Biotin
β-CD-Cy3.5
Exc
Tether structure
Key research milestones
Design and develop new QDs with broad emission wavelengths
Develop QD-surface ligands for water-compatibility and covalent conjugation
Optimization of QD-acceptor FRET spectral overlap and separation distances
Sensor optimization by linker and donor-acceptor pairs
Design and optimization of multireceptor QD-bioconjugates
Develop sensors that target analytes of interest to the Navy– TNT– RDX – Toxins– Pathogens– Environmental contaminant
Collaboration with:• Professor M.G. Bawendi and his group at MIT• Professor S. Simon and his group at Rockefeller UniversityFunding from ONR, Keith Ward program
Publications• 14 refereed publications, 1 patent, 9 proceedings, and 3 book
chapters
Work highlighted in Science, Nature Biotechnology, and Small Time magazine
Seminal papers:• H. Mattoussi, J.M. Mauro, E.R. Goldman, G.P. Anderson, V.C. Sundar, F.V.
Mikulec and M.G. Bawendi, J. Am. Chem. Soc. 122, 12142-12150 (2000).• E.R. Goldman, G.P. Anderson, P.T. Tran, H. Mattoussi, P.T. Charles, and J. M.
Mauro, Analytical Chemistry 74, 841-847 (2002).• J.K. Jaiswal, H. Mattoussi, J.M. Mauro, and S.M. Simon, Nature Biotechnology 21,
47-51 (2003).• I.L. Medintz, A.R. Clapp, H. Mattoussi, E.R. Goldman, and J.M. Mauro, Nature
Materials 2, 630-638 (2003).
Acknowledgments:
