Biogenic Silver Nanoparticles from Alternanthera philoxeroides (Mart.) Griseb: Synthesis, Characterization and Bioapplications

Abstract

Silver nanoparticles have diverse applications, particularly in health and medicine, emphasizing the need for costeffective, eco-friendly, and scalable production methods. Green synthesis forms nanoparticlesof silver throughbioreduction of silver ions, provides a sustainable alternative that eliminates the requirement for external reducing agents. This study highlights the efficiency of AgNPs synthesized by leaf aqueous extract of Alternanthera philoxeroides. The biosynthesized nano-sized particles were characterized using UV-Vis and FTIR spectroscopy. Morphological analysis via Electron Scanning Microscopy and Electron Transmission Microscopy revealed spherically shaped nanoparticles (AP-AgNPs) ofvarious sizes from 13-43 nm. The antimicrobial properties of APAE and APAgNPs were assessed using diffusion assay against microbial strains including S. aureus MTCC 11949, B. subtilis MTCC 10010, E. coli MTCC 9721, P. aeruginosa MTCC 9800, and A.niger MCIN 512, where AP-AgNPs exhibited notable antimicrobial activity. Furthermore, the cytotoxic effects of APAgNPs were assessed in contrast to MCF-7 and HCT-116 cell lines, yielding IC₅₀ values of 7.33 μg/mL and 13.15 μg/mL, respectively, compared to the positive control cisplatin (IC₅₀: 3.17 μg/mL & 6.24 μg/mL). These observations suggest that the synthesized silver nanoparticles exhibitprominent antimicrobial and anticancer properties, making them valuable for future applications in biomedical research, drug delivery systems and healthcare.