Electrosynthesis of tunable NiO/CuO-printed circuit board electrodes for glucose sensing

Abstract

In this research work, a copper-based printed circuit board (Cu-PCB) was used as an electrode substrate. Alloyed copper-nickel oxides were synthesized on the surface of the Cu-PCB electrode by the two stages: In the first step, the electrodeposition of copper-nickel alloy on the surface of the Cu-PCB electrode was carried out by cyclic chronopotentiometric method (8 cycles) at the optimized conditions. In the second step, the Ni/Cu-PCB electrode was immersed in 1 M NaOH electrolyte solution, followed by the electrochemical synthesis of the alloyed copper-nickel oxides by repetitive cyclic voltammetry (40 cycles) and subsequently, the NiO/CuO-PCB electrode was obtained. The surface structure and morphology of NiO/CuO-PCB and Cu-PCB electrodes were comparatively investigated by SEM, EDX, and XRD techniques. Moreover, the electrochemical behavior and electrocatalytic properties of NiO/CuO-PCB electrode have been effectively investigated. To study the electrocatalytic efficiency of the NiO/CuO-PCB electrode, the measurement of glucose as a biological target was studied by cyclic voltammetry (CV) and amperometry approaches as well. The limit of glucose detection (LOD) and sensitivity of the proposed method in glucose assay were calculated as 5.4 and 1.1 µM, and 118.14 and, 112.08 mA/M by CV and amperometry approaches, respectively. Two-segment calibration graphs were found over the range 1.4–120 mM by CV, and 0.14–180 mM by hydrodynamic amperometry techniques. The fabricated sensor was successfully used to measure glucose in blood serum and human plasma samples.