Supporting Information

Highly Sensitive Porous Carbon and Metal/Carbon Conducting Nanofiber Based Enzymatic Biosensors

for Triglyceride Detection

Kunal Mondal,a, #,* Md. Azahar Ali,a Chandan Singh,b Gajjala Sumana,b Bansi D. Malhotra,b,c,* and Ashutosh Sharmaa,*

aDepartment of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India

bDepartment of Science and Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, National Physical Laboratory, New Delhi-110012, IndiacDepartment of Biotechnology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi-110042, India

Corresponding author email: kmondal@ncsu.edu, bansi.malhotra@gmail.com,

ashutos@iitk.ac.in *

Present Address

#Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, NC 27695, USA.

1

Fig. S1. Electrospinning setup for producing partially aligned nanofibers.

Fig. S2. Dependency of diameter of as-spun fiber on the polymer concentration and flow rate of the PAN/AgNO3 solution.

2

Fig. S3. Selected area EDX spectra of Ag/carbon hybrid fibers. (Fig 7)

Fig. S4. Histogram for calculating average number of particles from TEM micrograph. (400×400 nm2

image area was considered for calculation).

Fig. S5. FTIR spectra of (a) CNF, (b) AgNF, and (C) LIP-GLDH/AgCNF enzyme immobilized onto AgCNF.

3

10 20 30 40 50

600

900

1200

100 %

100 %

89.3 %87.4 %

91.4 %

Lip-GLDH/CNF Lip-GLDH/AgCNF

Curr

ent (A

)

Days

Fig. S6. CV response of Lip-GLDH/CNF (i) electrode as a function of scan rate [20-100 mV/s] and anodic/cathode peak current verses square root of scan rates plots (ii).

Fig. S7. CV response of Lip-GLDH/AgCNF (i) electrode as a function of scan rate [20-100 mV/s] and anodic/cathode peak current verses square root of scan rates plots (ii).

4

Fig. S8. Stability studies of the Lip-GLDH/CNF (black) and Lip-GLDH/AgCNF bioelectrodes (red).

-0.4 0.0 0.4 0.8

-800

-400

0

400

800(i)

TGA + Ascorbic Acid TGA + Cholesterol TGA + Glucose TGA + LDL TGA TGA + Urea

Curr

ent (

A)

Voltage (V)-0.4 0.0 0.4 0.8

-800

-400

0

400

800 (ii)

TGA+Ascorbic Acid TGA+ Cholesterol TGA+ Glucose TGA+ LDL TGA+ Urea TGA

Curr

ent (

A)

Voltage (V)

A.A. Urea LDL Chol Glu TGA

720

750

780

810

840

870 (iii)

RSD=

2.0

3 %

RSD=

0.6

5 %

LDL= Low density lipoproteinChol= CholesterolGlu= GlucoseTGA= Triglycerides

Lip-GLDH/AgCNF Lip-GLDH/CNF

Curr

ent (

A)

Interferents

Fig. S9. CV response curves for Lip-GLDH/CNF (i) and Lip-GLDH/AgCNF (ii) bioelectrodes in presence various interferents. (iii) Peak current verses interferents histogram plots.

5

-0.4 0.0 0.4 0.8

-800

-400

0

400

800 (i)

Electrode 1 Electrode 2 Electrode 3 Electrode 4 Electrode 5 Electrode 6

Lip-GLDH/CNF's electrode responses

Curr

ent (

A)

Voltage (V)-0.4 0.0 0.4 0.8

-800

-400

0

400

800

(ii)

Electrode 1 Electrode 2 Electrode 3 Electrode 4 Electrode 5 Electrode 6

Lip-GLDH/AgCNF's electrode responses

Curr

ent (

A)

Voltage (V)

Elec 1 Elec 2 Elec 3 Elec 4 Elec 5 Elec 6550

600

650

700

750

800(iii)

RSD: 1.67 %

RSD: 1.52 %

Lip-GLDH/AgCNF Lip-GLDH/CNF

Curr

ent (A

)

Electrodes

Fig. S10. CV response curves for various Lip-GLDH/CNF (i) and Lip-GLDH/AgCNF (ii) bioelectrodes. (iii) Plots for current verses various fabricated bioelectrodes at same condition histogram plots.

Schematic S1. The proposed enzymatic reaction for detection of the triglyceride.

6

Table T1

EDX data showing the composition of Ag/CNF nanofibers carbonized at 900 °C.

Element Weight% Weight%σ Atomic%

Carbon 42.833 0.712 65.224

Silicon 50.399 0.657 33.628

Silver 6.768 0.483 1.147

Table T2

Value of HET constant and time constant for various fabricated electrodes.

Electrodes Diffusion co-efficient (cm2/s)

Electrochemicalarea (cm2)

HET constant (cm

s−1)

Time constant (τ)

CNF/ITO 0.000139 0.903 16.8×10-8 0.063Lip-GLDHCNF/ITO

0.000092 0.943 15.8×10-8 0.072

AgCNF/ITO 0.000173 0.94 19.3×10-8 0.014Lip-GLDH

AgCNF/ITO0.000229 1.12 20.9×10-8 0.0106

7