The antimicrobial applications of green synthesized ZnO nanoparticles by pomegranate peel extract

Pomegranate peel extract (PPE) facilitated the green hydrothermal synthesis of zinc oxide nanoparticles (ZnO NPs). X-ray diffraction revealed well-defined peak characteristics of the hexagonal wurtzite phase of ZnO NPs, with an average crystallite size of 23.13 nm. The surface morphology from the FESEM images displays a nanorod and flower-like nanostructure, with rod diameters and lengths ranging from 75 to 95 nm and less than 1 μm, respectively. The optical characteristics from diffuse reflectance spectroscopy showed that the absorption edge lies in the UV region, and the optical energy gap is about 3.23 eV. The antioxidant activity for free radical scavenging capacity of ZnO NPs was evaluated using the 2,2–diphenyl-1-picrylhydrazylhydrate (DPPH) assay, with varying concentrations of ZnO NPs, which demonstrated scavenging activity with an IC 50 of 0.079 mg/ml (79 μg/ml). Based on the results obtained, the green-synthesized ZnO NRs and NPs exhibit high antioxidant activity, making them potentially useful for treating disorders caused by free radicals. The antimicrobial activities of the green-synthesized ZnO NPs were assessed using the well diffusion assay, revealing the strongest antibacterial activity (inhibition zone of 29 mm) against Staphylococcus aureus , while the lowest activity was observed (inhibition zone of 13 mm) against Escherichia coli bacteria. This study also combines nanotechnology and microbiology to improve and develop new microbial and antioxidant agents of low cost and high activity. • ZnO NPs were green-synthesized using Pomegranate peel extract by the hydrothermal method. • ZnO hexagonal wurtzite phase, with an average crystallite size of 23.13 nm. • Nanorod and flower-like nanostructure, mixed shapes of the synthesized NPs. • The antioxidant activity for the free radical scavenging capacity of ZnO NPs was evaluated. • Strongest antibacterial activity (inhibition zone of 29 mm) against Staphylococcus bacteria.