Fabrication of non-enzymatic glucose sensor dependent upon Au nanoparticles deposited on carboxylated graphene oxide

In this article, Au nanoparticles (AuNPs) were deposited on carboxylated graphene oxide (GO-COOH) for the electrochemical oxidation and enzyme-free voltammetric and amperometric determination of glucose. The GO-COOAu modified glassy carbon electrode (GCE) exhibited good sensitivity and stability toward glucose electro-oxidation in alkaline media. The surface morphology of the as-prepared nanocomposite was investigated by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The electrochemical characterization of the working electrodes was evaluated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and amperometry. The GO-COOAu/GCE sensor provided excellent electro-catalytic performance for glucose oxidation with a linear range from 0.02 to 4.48 mM (R2 = 0.9919) at +0.35 V, a low limit of detection (LOD) of 6 μM, and a high sensitivity of 20.218 μA mM−1 cm−2. The GO-COOAu nanocomposite modified working electrode with high sensitivity, repeatability, reproducibility, and quantification of glucose in human serum samples made it a promising material for the development of non-enzymatic sensors.