Mediator enhanced glucose detection using organic–inorganic hybrid supramolecular assembly on gold electrodes

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 781; pp. 190 - 197
• Main Authors: Sahraoui, Yosra, Chaalia, Sana, Maaref, Abderrazak, Haddad, Amor, Bessueille, Francois, Jaffrezic-Renault, Nicole
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-11-2016; Elsevier Science Ltd; Elsevier
• Subjects: Analytical chemistry; Biosensors; Chemical reactions; Chemical Sciences; Crosslinking; Electrocatalysis; Electrochemical analysis; Electrodes; Electron transfer mediator; Enzyme biosensor; Glucose oxidase; Glutaraldehyde; Gold; Hybrid composites; Hybrid polyoxometalates; Hydrogen peroxide; Hydrogen peroxide detection; Infrared radiation; Molecular physics; Molecules; Multilayers; Nanoparticles; Reduction; Response time; Hybrid polyoxometalates; Glucose oxidase; Electron transfer mediator; Enzyme biosensor; Hydrogen peroxide detection
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2016.09.018

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 <10s. The H2O2 response at the modified electrode displays a linear response ranging from 40μM to 10mM.
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 40μM to 10mM with a sensitivity of 15.0μAmM−1.
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•A film of (APy)6[H2W12O40] composite was deposited on a AuNPs/gold electrode.•Electrocatalytic activity of the hybrid film towards H2O2 was optimized.•The anodic peak maximum at −0.8V was linear versus H2O2 concentration.•Glucose oxidase was cross-linked on the hybrid film.•The resulting glucose biosensor exhibits a sensitivity of 15.0μAmM−1 for glucose.