Biosynthesis Of Zinc Oxide Nanoparticles Using Moringa Oleifera Leaf Extract And Their Antibacterial Activity Against Multidrug-Resistant Staphylococcus Aureus

Abstract

The increasing prevalence of multidrug-resistant (MDR) pathogens such as Staphylococcus aureus has created an urgent need for alternative antimicrobial strategies. In this study, zinc oxide nanoparticles (ZnO NPs) were synthesized using Moringa oleifera leaf extract via a green biosynthesis approach. The phytochemicals in M. oleifera served as reducing and stabilizing agents, leading to the formation of stable ZnO NPs. The nanoparticles were characterized using UV–Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The antibacterial activity of the ZnO NPs was evaluated against MDR S. aureus using the agar well diffusion method and minimum inhibitory concentration (MIC) assays. Results revealed that the biosynthesized ZnO NPs exhibited a distinct absorbance peak around 370 nm, confirming their formation, with an average crystalline size of 25–35 nm. FTIR analysis indicated the presence of functional groups from M. oleifera phytochemicals responsible for capping the nanoparticles. Antibacterial assays demonstrated a significant inhibition zone (18.6 ± 0.5 mm at 1 mg/mL), surpassing that of the crude leaf extract (9.8 ± 0.4 mm). The findings suggest that M. oleifera-mediated ZnO NPs possess potent antibacterial properties, indicating their potential as eco-friendly and cost-effective alternatives for combating MDR pathogens.