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

The authors report that CuO x /NiO y hollow nanocomposites 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 NiCl 2 during the solvothermal etching process, and core-shell, yolk-shell or hollow structures can be obtained. The porous hollow structure composite of type CuO 30 /NiO 90 was used to modify a glassy carbon electrode. It exhibits excellent electrocatalytic activity towards glucose oxidation in solution of pH 13, typically at a working potential of +0.60 V (vs. Ag/AgCl). This enables voltammetric sensing of glucose with (a) a low limit of detection (0.08 μM, at S/ N  = 3), (b) over a wide linear range (0.20 μM - 2.5 mM), and (c) high sensitivity (2043 μA·mM −1 ·cm −2 ). The sensor is reproducible, selective and stable. It can be used to detect glucose in spiked human serum. The CuO 30 /NiO 90 composite also displays good electrocatalytic activity towards reduction of H 2 O 2 in neutral aqueous medium, typically at an applied potential of −0.35 V. It has a detection limit of 90 nM, a sensitivity of 271.1 μA·mM −1 ·cm −2 , and a linear detection range that extends from 0.30 μM to 9.0 mM. CuO x /NiO y nanocomposites with three different structures were synthesized by coordinated etching precipitation method. The hollow structure CuO 30 /NiO 90 was coated on the surface of glassy carbon electrode for the amperometric determination of glucose and hydrogen peroxide.