INVESTIGATING THE ANTIMICROBIAL AND ANTIOXIDANT PROPERTIES OF COPPER DOPED ZINC OXIDE NANOPARTICLES AGAINST SOME ORGANISMS

ABSTRACT Nanotechnology has emerged as a transformative field in material science, enabling the design of novel nanostructures with enhanced properties. This study focused on the synthesis, characterization, and evaluation of the antimicrobial and antioxidant properties of copper-doped zinc oxide nanoparticles (Cu-ZnO NPs). The nanoparticles were synthesized via the coprecipitation method using zinc acetate dihydrate and copper acetate as precursors. The assynthesized nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX) to confirm their crystalline structure, morphology, and elemental composition. TEM images revealed predominantly spherical nanoparticles, while EDX confirmed the successful incorporation of copper into the ZnO lattice. The antimicrobial activity of the synthesized Cu-ZnO NPs was evaluated against ten clinical isolates, including Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis), Gram-negative bacteria (Klebsiella pneumoniae, Proteus mirabilis, Shigella sonnei, Salmonella enterica, Pseudomonas aeruginosa), and fungi (Candida albicans, Candida krusei), using agar well diffusion and minimum inhibitory concentration (MIC) assays. The results demonstrated significant antimicrobial activity, with inhibition zones ranging from 13.00 mm to 30.00 mm and MIC values between 50–3.125 mg/ml. Additionally, the antioxidant potential of the nanoparticles was determined using the DPPH assay, showing a concentrationdependent radical scavenging activity with a maximum inhibition of 88.64% at 1.0 mg/ml, comparable to ascorbic acid (93.71%). The findings indicate that copper doping enhances the antimicrobial and antioxidant properties of ZnO nanoparticles, making Cu-ZnO NPs a promising low-cost alternative for combating microbial infections and oxidative stress in biomedical and food preservation applications.