Background: Nanoparticle applications are expanding across biomedical research.Plant extract-mediated (green) synthesis offers a sustainable and economically viable route for nanoparticle production.Objective: This study focused on the synthesis of gold nanoparticles (AuNPs) using Zataria multiflora Boiss extract and evaluated their antibacterial efficacy.Methods: AuNPs were synthesized using the aqueous extract of the Z. multiflora plant.The nanoparticles were characterized by UV-Vis spectroscopy, energy-dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and zeta-potential measurements.The total phenolic content of the Z. multiflora extract was quantified using a gallic acid standard curve.Flavonoid content was measured using quercetin as the standard.Antioxidant capacity was assessed with ascorbic acid as the reference standard.The antibacterial activity of the synthesized AuNPs was evaluated by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and by disk diffusion assays.Results: Spectroscopy showed a peak for AuNPs at 530 nm.DLS revealed an average hydrodynamic diameter of 123.8 nm with a moderate size distribution.The zeta-potential was highly negative (-77.7 mV), indicating colloidal stability.AuNPs exhibited significant antibacterial activity against both S. aureus and E. coli in MIC, MBC, and disk diffusion assays.Conclusion: Z. multiflora extract effectively mediates the biosynthesis of stable AuNPs with notable antibacterial activity, supporting its potential for green nanomaterial synthesis in antimicrobial applications.
Mahmoudi et al. (Mon,) studied this question.