Abdul Aji, Stevan Ronald Gulo, Muhammad Yogi Saputra, Refsya Azanti Putri, Tantri Liris Nareswari, Sukrasno, Amalia Kurnia Amin
Gold nanoparticles (AuNPs) have captured considerable interest on account of their distinctive structural and functional characteristics, rendering them highly promising for multiple healthcare uses, particularly in antioxidant and antimicrobial therapies. Nonetheless, the green synthesis of AuNPs continues to pose a challenge and necessitates further investigation. This study aimed to biosynthesize gold nanoparticles derived from A. mangium leaf extract (AuNPs-Am) by utilizing the previously underexplored extract as a reducing and stabilizing agent. AuNPs-Am was monitored using various techniques, including UV-Vis, FTIR, XRD, TEM, FE-SEM EDS, DLS, and zeta potential measurements. The findings indicated that the ideal environmentally-friendly synthesis of AuNPs-Am was achieved by combining 10 mL of 200 ppm HAuCl4 with 10 mL of leaf extract under acidic conditions at 50 °C for 90 min. TEM analysis disclosed that the AuNPs-Am predominantly manifested a globular structure, with a mean diameter of 7.13 ± 2.14 nm and a zeta potential of -11.9 mV, implying excellent colloidal robustness. The DPPH assay indicated that AuNPs-Am displayed a 3.4-fold increase in free radical scavenging capacity compared to the leaf extract alone, with IC50 of 95.99 mg/L. Antibacterial assays demonstrated that AuNPs-Am, at a dosage of 0.05 mg/mL, exhibited considerable inhibitory effects on Escherichia coli and Staphylococcus aureus, producing growth inhibition radii of 18.8 and 13.6 mm, sequentially. These results suggest that the biosynthesized AuNPs-Am possess promising antioxidant and antibacterial properties, highlighting their potential for applications in pharmacology, healthcare, and the food industry. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.
Department of Chemistry, Faculty of Science, Institut Teknologi Sumatera, Lampung Selatan, 35365, Indonesia; Department of Pharmacy, Faculty of Science, Institut Teknologi Sumatera, Lampung Selatan, 35365, Indonesia; Department of Pharmaceutical Biology, School of Pharmacy, Institut Teknologi Bandung, Bandung, 40132, Indonesia; Research Center for Chemistry, National Research, and Innovation Agency (BRIN), Kawasan Puspiptek Serpong, Banten, Tangerang Selatan, 15314, Indonesia