A Highly Sensitive Non-Enzymatic Glucose Electrochemical Sensor Electrode Material of CuO Nanospheres/Activated Carbon Composites

Abstract

The electrode materials of copper oxide (CuO) nanospheres composite activated carbon (AC) (CuO/AC) were prepared by a hydrothermal method. CuO/AC and chitosan (CTS) were immobilized on the surface of the glassy carbon electrode (GCE) to construct a non-enzymatic glucose electrochemical sensor (CuO/AC + CTS + GCE). The results show that an average particle size of spherical CuO is about 500 nm, which evenly distribute on the surface of AC. The nanocomposites have a large surface area, more active sites, and higher electron transfer ability. CuO/AC + CTS + GCE-2 with a Cu²⁺ and AC molar ratio of 1 : 2 enhanced electrocatalytic activity toward the oxidation of glucose in alkaline media. It displays a fast response to glucose with a high sensitivity of 2073.6 μA mM^–1 cm^–2, a good linear concentration range from 0.2 to 2400 μM, a low detection limit of 0.1 μΜ (S/N = 3), and fast current response of 5 s. The sensor is highly selective to glucose in the presence of commonly interfering species. CuO/AC as electrode materials has the potential application for a cost-effective, non-enzymatic glucose electrochemical sensor.