Green Synthesis of Silver Nanoparticles Using Ammoides pusilla Extract: Optimization, Characterization, and Antimicrobial Activity

The use of plant resources for the biosynthesis of metallic nanoparticles is a key component of green nanotechnology and represents a sustainable alternative to conventional chemical methods. While the synthesis of silver nanoparticles (AgNPs) using various plant extracts has been widely reported, the influence of Ammoides pusilla (Brot.) Breistr extract composition and synthesis parameters on AgNP formation has received limited attention. This study aimed to optimize the plant‐mediated synthesis of AgNPs using A. pusilla extract as a reducing and stabilizing agent. The effects of temperature, pH, reaction time, AgNO 3 concentration, and plant extract concentration on nanoparticle formation were investigated. The AgNPs were characterized by XRD, FTIR, UV–visible spectroscopy, TGA, and TEM. Optimal AgNP synthesis was achieved using 10% (w/v) A. pusilla extract, 3 mM AgNO 3 , pH 9, at 80°C for 2 h. TEM showed predominantly spherical AgNPs with particle sizes of 12–18 nm, while XRD indicated a crystallite size of 17 nm. The biosynthesized AgNPs exhibited enhanced antimicrobial activity over the plant extract, producing inhibition zones of 20.33 ± 0.58, 20.67 ± 0.58, 30.33 ± 0.58, 25.67 ± 0.58, and 21.00 ± 1.00 mm against Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Bacillus cereus , and Staphylococcus aureus , respectively.