One-step electrochemical fabrication of a nickel oxide nanoparticle/polyaniline nanowire/graphene oxide hybrid on a glassy carbon electrode for use as a non-enzymatic glucose biosensor

Abstract

We propose here a novel non-enzymatic glucose biosensor composed of a nickel oxide nanoparticle/polyaniline nanowire/graphene oxide hybrid composite on a glassy carbon electrode (NiONP/PANiNW/GO/GCE). The composite, prepared by mixing aniline with graphene oxide (GO) together, was transferred onto the surface of a bare glassy carbon electrode (GCE). This was then immersed in deoxygenated 50 mM NiCl₂ solution and electrodeposited at −0.8 V for 400 s to obtain the modified electrode, NiONP/PANiNW/GO/GCE. We characterized the morphology and electrochemical performance of the modified electrode using scanning electron microscopy (SEM) and cyclic voltammetry (CV), respectively. We found that the NiONP/PANiNW/GO/GCE exhibits higher electrocatalytic activity for glucose oxidation than a nickel oxide nanosheet/graphene oxide modified glassy carbon electrode (NiONS/GO/GCE) in alkaline solution. The sensitivity of the sensor towards glucose oxidation is 376.22 μA mM⁻¹ cm⁻² with a linearity range of 2 μM to 5.560 mM and a detection limit of 0.5 μM (S/N = 3). The sensor selectively detects glucose in the presence of common interfering species such as ascorbic acid, uric acid and dopamine. Furthermore, we examined the applicability of this modified electrode as a sensing probe for the detection of glucose concentration in fetal bovine serum. We conclude that the highly selective and sensitive NiONP/PANiNW/GO/GCE based non-enzymatic glucose sensor has the potential to be applied to the accurate measurement of glucose levels for various practical purposes such as clinical diagnosis and food analysis, etc.