Development of Non-enzymatic Electrochemical Glucose Sensor Based on Graphene Oxide Nanoribbon - Gold Nanoparticle Hybrid

This study focuses on enhancing the catalytic activity of gold nanoparticles (AuNPs) by using graphene oxide nanoribbons (GONRs) as a functional supporting matrix for a non-enzymatic glucose sensor operating under neutral condition. The proposed method for electrode fabrication offers the ability to control the GONR and AuNP loading for optimum catalytic performance. In our catalytic system, AuNPs supported by GONRs was profoundly superior to the unsupported conventional bare gold electrode, with a greatly enhanced current density (≈200%). This is attributed not only to the high total surface area of the AuNPs compared to that of a Au sheet, but also to the three-dimensional specific interaction between the functional groups on the GONRs and the Au active sites with the reactant and the intermediates that promote the reaction kinetics. The sensitivity of the AuNP/GONR hybrid electrode was examined through chronoamperometry and linear sweep voltammetry methods, and achieved a linear range from 0.5 μM to 10 mM, covering the normal glucose level in human blood. The poisoning effect of chloride ions was overcome by utilising an optimised polypyrrole-Nafion membrane, opening the possibility of the application of our electrode in continuous glucose monitoring for diabetic patients.