A non-enzymatic sensor based on three-dimensional graphene foam decorated with Cu-xCu2O nanoparticles for electrochemical detection of glucose and its application in human serum.

Abstract

In the present study, a porous structure consisting of three-dimensional graphene (3DG) decorated with Cu-based nanoparticles (NPs) (Cu or Cu-Cu2O) was synthesized in order to develop an enzyme-free electrochemical glucose sensor. Moreover, the effects of Cu-based nanoparticle concentrations on electrochemical properties and glucose detection were evaluated by cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry. Cu-based NPs@3DG showed markedly better electrochemical performance in glucose oxidation in alkaline solution compared to 3DG foam. Moreover, Cu-Cu2O NPs@3DG foam with the lowest concentration of Cu precursor showed excellent performance in glucose detection. A high sensitivity of 230.86 μA mM-1 cm-2 was obtained for this electrode in a linear range of 0.8-10 mM (R2 = 0.9951) and a detection limit of 16 μM. This sensor also showed good repeatability (relative standard deviation of 1.02%) and high selectivity (no observation of significant interference by interfering species such as ascorbic acid, dopamine, urea, and acetaminophen). The results confirmed that this electrode could be applied as a feasible and inexpensive non-enzymatic electrochemical glucose sensor.