ANTIMICROBIAL POTENTIAL OF GOLD NANOPARTICLES BIOSYNTHESIZED USING WATER EXTRACT OF DIOSPYROS CELEBICA SEEDS: SYNTHESIS AND CHARACTERIZATION

This investigation explores gold nanoparticles (Au-NPs) biosynthesis employing Diospyros celebica seeds water extract and evaluates their antimicrobial potential. Au-NPs were synthesized by mixing chloroauric acid with the plant extract, followed by incubation at 60°C, leading to a color change indicative of nanoparticle formation. Characterization using UV-Vis spectrophotometry, zeta potential analysis, and transmission electron microscopy confirmed successful synthesis, revealing an average particle size of 28.10 nm and a negative zeta potential of -1.20 mV, suggesting stability due to bioactive compounds in the extract. High-magnification TEM images showed Au-NPs with diverse morphologies, including spherical, rod-shaped, triangular, cubic, pentagonal, hexagonal, and diamond like structures. Fourier-transform infrared spectroscopy (FTIR) analysis identified hydroxyl, carboxylic acid, carbonyl, amide, and carbon-hydrogen functional groups as key contributors to nanoparticle biosynthesis. Antimicrobial action was valued using the minimum inhibitory concentration (MIC) method toward Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Results proved no antibacterial activity, indicating that the biosynthesized Au-NPs are non-toxic to living organisms. This research highlights D. celebica as a sustainable resource for eco-friendly Au-NP synthesis through green chemistry approaches.