Hybrid ZnO-CuO nanoparticles: for MCPE in dopamine detection, dye degradation, and antibacterial assessment

Abstract

The hybrid ZnO-CuO nanoparticles were synthesized using the hydrothermal method. Structural characteristics were assessed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM) techniques. The nanoparticles were integrated into a carbon paste electrode to explore its potential for voltammetric detection of dopamine. The modified carbon paste electrode (MCPE) was used for electrochemical response to evaluate dopamine in a pH 7.2 PBS solution, with a scan rate of 50 mVs⁻¹. The electrode modification facilitated the individual determination of dopamine through cyclic voltammetry analysis. Analysis of the voltammograms from the oxidation studies indicated that the hybrid ZnO-CuO nanoparticles demonstrate superior catalytic activity in dopamine oxidation. Additionally, the photocatalytic capabilities of the hybrid ZnO-CuO nanoparticles were assessed in degrading both cationic and anionic dyes. For crystal violet, which is a cationic dye, 1 mg/L of the concentration of ZnO-CuO showed a maximum of 82.93% degradation, and complete degradation of Cry.V dye was observed in less than 30 min at pH 12.0. Furthermore, the nanoparticles showed higher efficacy against gram-positive bacteria than gram-negative bacteria, as determined by disc diffusion tests against Staphylococcus aureus and Escherichia coli.