Direct electrochemistry of glucose oxidase and sensing of glucose at glassy carbon

electrode modified with reduced graphene oxide/fullerene-C60 composite

Balamurugan Thirumalraj, a‡ Selvakumar Palanisamy, a‡ Shen-Ming Chen a* Cheng-Yu

Yang, a Prakash Periakaruppan b** and Bih-Show Lou c***

aDepartment of Chemical Engineering and Biotechnology, National Taipei University of

Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan (ROC).

bPost Graduate and Research Department of Chemistry, Thiagarajar College, Madurai-625009,

Tamilnadu, India.

c Chemistry Division, Center for Education, Chang Gung University, 259, Wen-Hwa 1st Road,

Kwei-Shan, Tao-Yuan 333, Taiwan, ROC

*Corresponding author. Fax: +886 2270 25238; Tel: +886 2270 17147, E-mail:

smchen78@ms15.hinet.net (S.M. Chen)

Supporting information

Electronic Supplementary Material (ESI) for RSC Advances.This journal is © The Royal Society of Chemistry 2015

Fig. S1 A) CV response of RGO–C60/GOx modified electrode in N2 saturated PBS at the scan

rates from 10 to 200 mV s–1. B) The corresponding calibration plot for Ipa and Ipc of redox couple

vs. scan rate.

Fig. S2 A) CV response obtained at RGO–C60/GOx modified electrode in N2 saturated different

pH solutions (3–9) at a scan rate of 50 mV s-1. B) Calibration plot for the pH vs. E0’.

Fig. S3 A) CV response of RGO–C60/GOx modified electrode in presence of oxygen (a) and N2

saturated PBS at a scan rate of 50 mV s–1. CV response of RGO–C60/GOx modified electrode

for absence (a) and presence of different concentration (0.5 to 5.5 mM, b–g) of glucose in

oxygen saturated PBS.

Fig. S4 Amperometric i-t response obtained at RGO–C60/GOx biosensor for the addition of 1

mM glucose (a), 5 mM ascorbic acid (b) and 5 mM dopamine (c) uric acid (d) and fructose (d)

into the constantly stirred oxygen saturated PBS; working potential is –0.42 V.

Fig. S5 The storage stability of the biosensor on the response to the detection of 1 mM glucose at

different periods of time.

Table ST1 comparison of analytical performance of the proposed glucose biosensor with

previously reported graphene and C60 based enzymatic glucose sensors.

Abbreviations

LR – linear response range; LOD – limit of detection; GR – graphene; Nf – nafion;

GOx – glucose oxidase; CV – cyclic voltammetry; TOAB+ – tetraoctylammonium bromide; ECL

– electrochemiluminescence; ERGO – electrochemically reduced graphene oxide; SDS – sodium

dodecyl sulfate; Chi – chitosan; MWCNT – multiwalled carbon nanotubes; GO – graphene

oxide; RGO – reduced graphene oxide

Modified electrodeMethod Sensitivity

(µA mM-1 cm-2)

LR

(mM)

LOD

(µM)Ref.

GR/Nf/GOx CV 21.9 2.0–14.0 40.0 J. Hui et al., 2013

C60/ TOAB+ ECL – 0.005 –13 0.17 C. Ye et al., 2014

ERGO/SDS/GOx CV 1.13 1.0–8.0 40.8 M. Shamsipur et al., 2014

GR/GOx/Chi CV 37.93 0.08–12.0 20.0 X. Kang et al., 2009

ERGO– MWCNT/GOx Amperometry 7.95 0.01–6.5 6 V. Mani et al., 2013

GO/MWCNT/GOx Amperometry 0.266 0.1–19.5 28.0 S. Palanisamy et al., 2014

RGO/GOx Amperometry 1.85 0.1–27.0 – B. Unnikrishnan et al., 2013

GR/Nf/GOx CV – 0.5–14.0 30.0 Z. Yanqin et al., 2012

RGO–C60/GOx Amperometry 55.97 0.1–12.5 35 Present work

Table. ST2 Determination of glucose in diluted human blood serum samples using RGO–

C60/GOx biosensor.

aStandard addition method.

bRelative standard deviation of 3 measurements.

Sample Added

(µM)

Founda

(µM)

Recovery

(%)

RSDb

1 0.5 0.48 95.0 3.9

2 1.0 0.95 97.5 3.1