Swati Pravin Pawar and Manisha Ramchandra Sapkal
Abstract
The biological synthesis of metal oxide nanoparticles offers a sustainable, cost-An ecologically sound, economical, and sustainable alternative for conventional chemical and physical procedures is the biological production of metal oxide nanoparticles. The fungus Aspergillus flavus is used in this study to produce Zinc Oxide Nanoparticles (ZnO NPs) extracellular, taking advantage of its strong metabolic profile and high protein secretion. Aspergillus flavus was successfully isolated from soil samples collected at various municipal waste dump sites from Sangli district Maharashtra, where the indigenous microflora exhibits enhanced tolerance to metallic stress. The fungal isolate was cultured in a submerged fermentation medium, and the resulting cell-free filtrate was reacted with Zinc sulphate. The synthesized ZnO NPs were purified through high-speed centrifugation and thermal treatment to eliminate biological residues. A distinctive surface plasmon resonance peak seen using UV-visible spectroscopy was the first indication that ZnO NPs had formed. The particlesâ hexagonal wurtzite structure and strong crystallinity were verified by X-ray diffraction (XRD) patterns. The presence of fungal proteins functioning as capping agents, guaranteeing long-term stability, was discovered by Fourier Transform Infrared (FTIR) research. Most of the particles were spherical and ranged in size from 20 to 50 nm, according to morphological evaluation using Scanning Electron Microscopy (SEM) and TEM. The potential of Aspergillus flavus isolated from contaminated environments as an effective bio-factory is highlighted by this study. Because of their favourable structural characteristics, the âgreenâ produced ZnO NPs are good choices for biological, environmental, and antibacterial applications.