Eco-Friendly Synthesis and Antibacterial Assessment of Zinc Nanoparticles from Arbutus unedo Leaf Extract

Abstract

This study investigates the synthesis, characterization, and antibacterial effects of zinc nanoparticles (ZnNPs) synthesized via a green synthesis method using Arbutus unedo leaf extract. The plant extract served as both a reducing agent and a stabilizer during the ZnNP synthesis. The obtained nanoparticles were characterized using UV-Vis spectrophotometry, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The UV-Vis spectrum exhibited a maximum absorption band at 371 nm, consistent with the surface plasmon resonance (SPR) of ZnNPs. According to the XRD analysis, the synthesized nanoparticles possessed a hexagonal wurtzite crystal structure with an average crystallite size of 17.37 nm (ranging between 14.41 and 19.33 nm), as calculated using the Scherrer equation. SEM images revealed that the ZnNPs formed flower-like nanostructures. EDX analysis confirmed that the synthesized nanoparticles comprised 60.9% Zn, 21.2% O, 17.5% Na, and 0.4% Ca. Antibacterial tests demonstrated that ZnNPs were effective against Escherichia coli and Staphylococcus aureus. Microdilution tests conducted on bacterial cultures indicated that the antibacterial effect of ZnNPs increased up to a concentration of 500 µg/mL (p < 0.05). The results manifest that ZnNPs synthesized using Arbutus unedo leaf extract exhibit biocompatibility, eco-friendliness, and high antibacterial activity. This study highlights that biogenic ZnNP synthesis offers a sustainable and effective alternative approach.