Self-assembly of phenoxyl-dextran on electrochemically reduced graphene oxide for nonenzymatic biosensing of glucose

Electrochemically reduced graphene oxide (ERGO) has attracted considerable interest in the electrochemical biosensing field. In this work, the pi-pi stacking assembly of phenoxyl-dextran (DexP) and sensitive electrochemical stripping analysis of gold nanoparticles (Au NPs) on the ERGO surface are conducted to develop a novel nonenzymatic glucose biosensing method. Concanavalin A (Con A) was covalently linked with Au NP to obtain a nanoprobe, which was used for the specific biorecognition of glucose at the ERGO/DexP biosensor. Based on the glucose-Con A-dextran competition reaction, the Au NP/Con A nanoprobes were quantitatively captured onto the biosensor surface. Through the electrochemical stripping analysis of Au NPs, sensitive signal transduction was achieved. ERGO not only enables the simple preparation of the biosensor but also improves the sensitivity of the method greatly. The high specificity of the Con A biorecognition and the relatively positive potential range for the gold stripping analysis exclude well the signal interferences involving in the conventional electrochemical glucose biosensors. Thus such a nonenzymatic glucose biosensing method featuring excellent performance, low cost and convenient signal transduction provides a great potential for the diabetes diagnosis application. (C) 2017 Elsevier Ltd. All rights reserved.