Green synthesis and characterization of crystalline silver nanoparticles from Phyllanthus maderaspatensis L. with enhanced efficacy against enteric pathogens over Amikacin

Green synthesis of metallic nanoparticles has emerged as a critical frontier in nanotechnology, offering environmentally compatible and bioactive alternatives to conventional toxic reduction methods. This study explores the untapped potential of Phyllanthus maderaspatensis leaf extract as a dual-action reducing and stabilizing agent for silver nanoparticle (AgNP) fabrication. AgNPs were synthesized by reacting aqueous leaf extract with 1 mM AgNO3 at room temperature. The resulting particles were characterized using UV-Visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Antibacterial efficacy was evaluated against Vibrio cholerae and Bacillus cereus using the disc diffusion method. The formation of crystalline AgNPs was confirmed by a characteristic surface plasmon resonance (SPR) peak at 477.5 nm. XRD analysis verified a face-centered cubic (FCC) structure with a calculated average crystallite size of 14 nm. FTIR spectra identified hydroxyl, carbonyl and amine functional groups as the primary bioactive moieties responsible for silver ion reduction and bio-capping. Notably, the synthesized AgNPs exhibited potent antibacterial activity with zones of inhibition reaching 19.1 mm for V. cholerae and 20.2 mm for B. cereus, the latter surpassing the performance of the standard antibiotic Amikacin. These findings demonstrate that P. maderaspatensis-mediated green synthesis of crystalline silver nanoparticles produces stable, small-scale AgNPs with superior antimicrobial properties against enteric pathogens. This study supports the integration of phyto-nanotechnology into biomedical frameworks for developing next-generation antimicrobial agents.