Phytomediated Fabrication of Zinc Oxide and Zinc Oxide Silver Nanocomposite Using <i>Mangifera indica</i> Leaf Extract: Characterization Antibacterial, Antibiofilm, Antioxidant Activity

ABSTRACT Metal and metal oxide nanoparticles have great value and widespread applications in various sectors, including the food industry, due to their antibacterial and antioxidant properties. In this study, zinc oxide and zinc oxide‐silver nanocomposites were synthesized using mango leaf extracts. The nanoparticles were characterized using UV‐visible spectroscopy, dynamic light scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, x‐ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). UV‐visible spectroscopy confirmed zinc oxide (ZnONPs) and zinc oxide‐silver (ZnO‐AgNPs) nanoparticles with peaks at 330 and 380 nm. The size and zeta potential of ZnONPs and ZnO‐AgNPs were 28.8 nm and −25.0 mV, 233.3 nm, and −56.20 mV, respectively. SEM and TEM analyses showed spherical, crystalline, and uniformly distributed nanoparticles. The nanoparticles exhibited antibacterial activity against Escherichia coli, Staphylococcus aureus , and Staphylococcus enterica and reduced biofilm formation against E. coli, S. aureus , and S. typhimurium . The biofilm inhibition percentage of ZnONPs ranged from 24 to 34 for E. coli , 23 to 53 for S. aureus , and 25 to 51 for S. typhimurium . The biofilm inhibition by ZnO‐AgNPs ranged from 26% to 49% for E. coli , 38% to 54% for S. aureus , and 32% to 38% for S. typhimurium . Comparatively, the ZnO‐AgNPs showed less toxicity, exhibited antimicrobial and antibiofilm activity. Overall, the synthesized ZnO‐AgNPs and ZnONPs demonstrated antioxidant, antibiofilm activity and showed low toxicity, making them promise for food applications. This study highlights the potential of mango leaf extract as a sustainable reducing agent for the synthesis of ZnO and ZnO‐Ag nanocomposites, which are eco‐friendly and cost‐effective. The antimicrobial, antibiofilm, antioxidant, low‐toxicity, and biocompatible properties of these green‐synthesized nanoparticles show promising potential for applications in food preservation and packaging, providing an environmentally friendly alternative to conventional chemical agents.