Green synthesis and characterization of zinc oxide nanoparticles using Monoon longifolium leave extract for biological applications

The present study deals with the biosynthesis of zinc oxide nanoparticles (ZnO NPs) using the Monoon longifolium ( M . longifolium ) leaf extract. The prepared ZnO NPs were characterized by XRD, FTIR, UV–Vis, TGA/DTA, and SEM. The synthesis parameters, such as plant extract volume (10–50 mL), heating duration (15 min), zinc nitrate concentration (1 mM), reaction time (1 h), and temperature (60 °C), were optimized. The synthesized ZnO NPs exhibited significant antibacterial activity against Staphylococcus aureus (22 ± 0.57 mm) and Escherichia coli (19 ± 1 mm), as well as antifungal activity against Candida albicans (21 ± 0.16 mm), as determined by the agar-well-diffusion method. The minimum inhibitory concentration (MIC) of ZnO-NPs against S. aureus (6.25µg/mL) and E. coli (12.5 µg/mL), respectively, while the minimum fungicidal concentration (MFC) was 25 µg/mL against Candida albicans . Additionally, the antioxidant activity of the ZnO NPs ranged from 0 to 78% (IC50 = 12.5 μg/mL). These results demonstrate the potential of the synthesized ZnO NPs as effective antibacterial, antifungal, and antioxidant agents.