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Graphene oxide for electrochemical sensing applications

DSpace at IIT Bombay

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Title Graphene oxide for electrochemical sensing applications
 
Creator ROY, S
SOIN, N
BAJPAI, R
MISRA, DS
MCLAUGHLIN, JA
ROY, SS
 
Subject GRAPHITE OXIDE
FUNCTIONALIZED GRAPHENE
IMPEDANCE SPECTROSCOPY
IMMUNOSENSOR
BIOSENSORS
SENSORS
SHEETS
AMPLIFICATION
PARTICLES
 
Description By exploiting the presence of abundant carboxylic groups (-COOH) on graphene oxide (GO) and using EDC-NHS (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride-N-hydroxysuccinimide) chemistry to covalently conjugate protein molecules, we demonstrate a novel electrochemical immunosensor for detection of antibody-antigen (Rabbit IgG-AntiRabbit IgG) interactions. The interactions were verified using Electrochemical Impedance Spectroscopy (EIS). Although GO is known to be a poor conductor, the charge transfer resistance (R(P)) of a GO modified glassy carbon electrode (GCE) was found to be as low as 1.26 Omega cm(2). This value is similar to that obtained for reduced graphene oxide (RGO) or graphene and an order of magnitude less than bare GCE. The EIS monitored antibody-antigen interactions showed a linear increase in R(P) and the overall impedance of the system with increase of antibody concentration. Rabbit IgG antibodies were detected over a wide range of concentrations from 3.3 nM to 683 nM with the limit of detection (LOD) estimated to be 0.67 nM. The sensor showed high selectivity towards Rabbit IgG antibody as compared to non-complementary myoglobin. RGO modified GCE showed no sensing properties due to the removal of carboxylic groups which prevented subsequent chemical functionalization and immobilization of antigen molecules. The sensitivity and selectivity achievable by this simple label free technique hint at the possibility of GO becoming the electrode material of choice for future electrochemical sensing protocols.
 
Publisher ROYAL SOC CHEMISTRY
 
Date 2012-06-26T09:31:50Z
2012-06-26T09:31:50Z
2011
 
Type Article
 
Identifier JOURNAL OF MATERIALS CHEMISTRY,21(38)14725-14731
0959-9428
http://dx.doi.org/10.1039/c1jm12028j
http://dspace.library.iitb.ac.in/jspui/handle/100/14294
 
Language English