Eco-Friendly Synthesis Of Zinc Oxide Nanoparticles Using Saraca Asoca Extract: Antifungal Activity Against Aspergillus Niger

Abstract

This work reports the green synthesis of zinc oxide nanoparticles (ZnO NPs) employing the aqueous extract of Saraca asoca, an ethnomedicinal plant valued for its diverse phytoconstituents. The phytochemicals present in the extract served as reducing and stabilizing agents for nanoparticle formation. The synthesized ZnO NPs were characterized by UV–Vis spectroscopy, FTIR, XRD, and SEM, which confirmed their nanoscale dimensions, crystalline structure, and surface functional groups. Antifungal efficacy was assessed against Aspergillus niger using the agar well diffusion method at concentrations ranging from 0.25 to 1.0 mg/mL. The nanoparticles exhibited a concentration-dependent inhibitory effect, producing the maximum zone of inhibition (18.6 ± 0.5 mm) at 1.0 mg/mL, whereas the crude extract displayed comparatively lower activity (9.8 ± 0.4 mm). These findings indicate that S. asoca-mediated ZnO NPs possess significant antifungal potential and can serve as an eco-friendly alternative to conventional antifungal agents in pharmaceutical and biomedical applications.