Optimization of photocatalyst ZnO and Cu integrated zno nanoflower structure by anodization and electrodeposition as antibacterial agent against biofilms / Nur Syuhada Mohd Haeizar

Biofilms are resilient bacterial communities posing significant health challenges. The integration of nanomaterials offers a promising way for combating bacterial biofilms. Metal oxide nanoparticles (NPs) and their nanocomposites have exhibited remarkable antimicrobial properties. This study explores the development of Cu-doped ZnO nanoflowers (Cu/ZnO NFs) as a promising strategy to combat bacterial biofilms. The aimed is to optimize the synthesis parameters of ZnO NFs using electrochemical anodization and investigate the effect of Cu nanoparticle (NPs) incorporation via electrodeposition on their photocatalytic and antibacterial properties. ZnO NFs were synthesized using different electrolyte concentrations, anodization times, and applied potentials. Cu NPs were then incorporated by varying the copper nitrate concentration and deposition time to control the density of Cu NPs coverage onto the surface of ZnO NFs. X-ray diffraction (XRD), Field-Emission Scanning Electron Microscope (FESEM) and Diffuse Reflectance Spectra (DRS) characterized the structure, morphology, and optical properties. Antibacterial activity against various bacterial strains was assessed through disc diffusion and semi quantitative adherence assay. The optimal ZnO NFs were obtained using a 50 mM sodium bicarbonate solution, 10 minutes anodization for 10 V, exhibiting uniform morphology, high crystallinity, and a low band gap. Cu/ZnO NFs with Cu NPs deposited at 6 mM copper nitrate for 120 seconds showed enhanced light absorption in the visible range and potentially reduced electron-hole recombination. Both ZnO NFs and Cu/ZnO NFs displayed good antibacterial activity, particularly against initial biofilm formation, likely through reactive oxygen species (ROS) generation.