A hollow CuOx/NiOy nanocomposite for amperometric and non-enzymatic sensing of glucose and hydrogen peroxide

The authors report that CuOx/NiOy hollownanocomposites are an effective bifunctional catalyst capable of oxidizing glucose and reducing hydrogen peroxide. Synthesis is based on a solvothermal process and subsequent thermal treatment. The structure can be controlled by adjusting the amounts of added NiCl2 during the solvothermal etching process, and core-shell, yolk-shell or hollow structures can be obtained. The porous hollow structure composite of type CuO30/NiO90 was used tomodify a glassy carbon electrode. It exhibits excellent electrocatalytic activity towards glucose oxidation in solution of pH13, typically at a working potential of +0.60V (vs. Ag/AgCl). This enables voltammetric sensing of glucose with (a) a low limit of detection (0.08M, at S/N=3), (b) over a wide linear range (0.20M - 2.5mM), and (c) high sensitivity (2043AmM(-1)cm(-2)). The sensor is reproducible, selective and stable. It can be used to detect glucose in spiked human serum. The CuO30/NiO90 composite also displays good electrocatalytic activity towards reduction of H2O2 in neutral aqueous medium, typically at an applied potential of -0.35V. It has a detection limit of 90nM, a sensitivity of 271.1AmM(-1)cm(-2), and a linear detection range that extends from 0.30M to 9.0mM.