Journal of Electroanalytical Chemistry, Vol.781, 296-303, 2016
One-pot electrodeposition of a composite film of glucose oxidase, imidazolium alkoxysilane and chitosan on a reduced graphene oxide-Pt nanoparticle/Au electrode for biosensing
A composite film of glucose oxidase (GOx), imidazolium alkoxysilane (ImAS, a silane-ionic liquid (IL) bifunctional reagent) and chitosan (CS) was electrodeposited in a one-pot manner on a reduced graphene oxide (RGO)-Pt nanoparticle (PtNP) modified Au electrode for biosensing of glucose. Cyclic voltammetry electroreduction of coexisting p-benzoquinone was used to lift the electrode-surface pH for the GOx-IMAS-CS deposition, as a result of deprotonation of CS and hydrolyzation/condensation of ImAS at lifted pH. The RGO-PtNP composite was prepared through mild room-temperature chemical reduction of graphene oxide and H2PtCl6 center dot 6H(2)O by formic acid, as characterized by UV-visible/FT-IR/Raman spectrophotometry, scanning electron microscopy and electrochemical techniques. The GOx-ImAS-CS/RGO-PtNP/Au electrode was used for glucose biosensing by anodically detecting the enzymatically generated H2O2 at 0.55 V versus SCE. Under the optimal conditions, the GOx-ImAS-CS/RGO-PtNP/Au electrode showed a linear amperometric response to glucose concentration from 2.0 mu M to 5.5 mM with a sensitivity of 84.4 mu A mM(-1) cm(-2) and a limit of detection of 0.02 mu M (S/N = 3), which is superior to GOx-CS/RGO-PtNP/Au, GOx-(IL-NH2)-CS/RGO-PtNP/Au, GOx-(3-aminopropyltriethoxysilane)-CS/RGO-PtNP/Au and GOx-ImAS-CS/Au electrodes as well as-many reported enzyme electrodes fabricated using similar materials. (C) 2016 Elsevier B.V. All rights reserved.
Keywords:Glucose oxidase-imidazolium alkoxysilane-chitosan composite film;pH-induced electrodeposition of enzyme film;Graphene oxide-Pt nanoparticle composite;Au electrode;Amperometric glucose biosensing