Mycosynthesis of silver nanoparticles from Pleurotus ostreatus extracts: antibacterial and catalytic activity evaluation

Biosynthesized silver nanoparticles (AgNPs) are attracting increasing attention due to their unique properties, including simplicity, cost-effectiveness, and eco-friendliness. In this study, AgNPs were successfully synthesized at room temperature using extracts from Pleurotus ostreatus (P. ostreatus). The resulting POS-AgNPs were characterized using UV-Vis spectroscopy, FTIR, TEM, and Zetasizer analysis. The UV-Vis spectra displayed a characteristic peak for AgNPs within the wavelength range of 250-800 nm, confirming successful nanoparticle formation. TEM analysis revealed uniform, spherical POS-AgNPs with an average size of approximately 19.9 nm and a zeta potential of -10.8 mV. FTIR spectroscopy confirmed the presence of functional groups involved in the reduction and stabilization of the nanoparticles. The green-synthesized PO-AgNPs exhibited potent antibacterial activity against the tested bacterial strains, showing greater efficacy compared to both the plant extract and AgNO3 alone. Among the tested bacteria, Pseudomonas aeruginosa was the most sensitive, showing the highest inhibition zone at a concentration of 100 µg/mL (15.6 ± 1.2 mm), followed by Bacillus cereus and Escherichia coli (13.2 ± 0.3 mm and 12.5 ± 0.5 mm, respectively). The concentration-dependent inhibition of bacterial growth suggests that PO-AgNPs are a promising antimicrobial agent. Furthermore, the catalytic activity of POS-AgNPs was evaluated by monitoring the reduction of 4-nitroaniline (4-NA) and 4-nitrophenol (4-NP). The nanoparticles demonstrated efficient catalytic activity, leading to the rapid degradation of these compounds. Thus, this study highlights P. ostreatus as a green and sustainable source for the synthesis of AgNPs with notable antibacterial and catalytic properties, holding significant promise for applications in healthcare and various industries.