Fabrication of copper oxide electrodes and investigation of acidity’s impact on biosensor performance

Abstract

Copper oxide (CuO) nanoparticles were synthesized through the chemical bath deposition (CBD) method on an FTO (fluorine tin oxide) substrate using a 0.1-M copper sulfate solution. The thin films were formed and used as working electrodes in a non-enzyme glucose sensor. The influence of the manufacturing acidity (pH 6, 8, 10, and 12) on the thin-film formation possibility, properties of copper oxide, and its performance as a glucose sensor were studied. Comprehensive standard analyses, including x-ray diffraction, ultraviolet–visible, scanning emission microscopy, and energy-dispersive x-ray were used to characterize the synthesized CuO thin films. Cyclic voltammetry measurements were conducted to evaluate the oxidation and reduction potentials of the CuO-based non-enzymatic glucose sensor. The sensing ability was tested by Amperometry measurement. The electrocatalytic performance of copper oxide for glucose detection was excellent and highly stable at pH 10. Structural analysis showed that the best nanostructures in terms of purity, film roughness, and substrate adhesion were formed at pH 10, which positively affected its sensor performance. The electrocatalytic performance of this film was good and stable. It also had the highest glucose sensitivity of 21.488 mA mM⁻¹ cm⁻² with a detection limit of 1.1 mM as indicated by Amperometric measurement. These results highlight the great potential of the CuO nanosensor as a non-enzymatic glucose device with high selectivity, cost-effectiveness, and simplicity.