Porous Cu–NiO modified glass carbon electrode enhanced nonenzymatic glucose electrochemical sensors

Abstract

Porous Cu–NiO nanocomposites were successfully prepared by calcination of the Cu–Ni(OH)₂ precursor at 400 °C for 2 h. During the process of calcination, Ar was used to deaerate O₂. The structure and morphology of Cu–NiO were characterized by X-ray diffraction spectrum (XRD), energy dispersive X-ray analyses (EDX), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Using porous Cu–NiO nanocomposites, a simple non-enzymatic amperometric sensor has been fabricated (Cu–NiO/GCE) and evaluated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and typical amperometric method. When applied to detect glucose by the amperometric method, Cu–NiO/GCE produced an ultrahigh sensitivity of 171.8 μA mM⁻¹, with a low detection limit of 0.5 μM (S/N = 3). What's more, interference from common co-existing species, such as UA, AA, and fructose can be avoided at the sensor. Results in this study imply that porous Cu–NiO nanocomposites are promising nanomaterials for the enzyme-free determination of glucose.