Journal of Electroanalytical Chemistry, Vol.781, 190-197, 2016
Mediator enhanced glucose detection using organic-inorganic hybrid supramolecular assembly on gold electrodes
In this study, a new organic-inorganic material, based on an alpha-metatungstate [H2W12O40](6-) cluster, was synthesized via the hydrothermal method by using aminopyridinium (APy)(+) cations as the hybrid material, and characterized by FT-IR and UV spectra analysis. The hybrid composite was immobilized on a gold electrode decorated with gold nanoparticles (AuNPs) and the modified electrode exhibited excellent electrocatalytic activities towards the reduction of H2O2 at neutral pH with a response time of <10 s. The H2O2 response at the-modified electrode displays a linear response ranging from 40 mu M to 10 mM. Based on the H2O2 reduction activity, the (APy)(6)[H2W12O40] composite was successfully used for the fabrication of a novel enzymatic glucose biosensor. The glucose oxidase enzyme (GOx) was immobilized onto the hybrid composite on AuNPs/gold electrodes; the (APy)(6)[H2W12O40] composites were used as both mediation and bridging molecules. A multilayer architecture was constructed from hybrid POM alternating with (GOx), using glutaraldehyde as a covalent attachment cross-linker. Cyclic voltammetry (CV), SWV and chronoamperometry were used to determine the electrochemical properties of the mediator and characterize its reaction with (GOx). The resulting glucose biosensor exhibits a wide linear response for glucose from 40 mu M to 10 mM with a sensitivity of 15.0 mu A mM(-1). (C) 2016 Elsevier B.V. All rights reserved.
Keywords:Hybrid polyoxometalates;Hydrogen peroxide detection;Glucose oxidase;Enzyme biosensor;Electron transfer mediator