Biosynthesis of Silver Nanoparticles Via Senna occidentalis: A Study on Their Structure and Evaluation of Antimicrobial Activity

This study explores a sustainable method for producing silver nanoparticles (AgNPs) through the use of Senna occidentalis leaf extract, while evaluating their antimicrobial potential against clinically relevant bacterial pathogens. The AgNPs were biosynthesized by reacting an aqueous extract of Senna occidentalis with a silver nitrate solution. To verify nanoparticle formation and analyze structural and elemental composition, the synthesized AgNPs were characterized using UV-Visible spectroscopy, FTIR, EDS, and TEM. Their antibacterial activity was assessed against Streptococcus pyogenes, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa via the agar well diffusion technique. The presence of an absorption peak at 331 nm in the UV-Vis spectrum confirmed the formation of AgNPs. FTIR analysis indicated that phytochemicals from the plant played a role in the synthesis, as shown by the –O-H stretch observed at 2893 cm⁻¹. EDS signals in the 3.0–3.5 keV range confirmed the presence of silver, while TEM imaging revealed moderately clustered nanoparticles with an average size near 100 nm. The AgNPs exhibited a concentration-dependent antibacterial effect. These results demonstrate that Senna occidentalis is an effective mediator for green synthesis of silver nanoparticles with notable antimicrobial properties. The findings support the use of this method as a safe, affordable, and sustainable approach to developing antimicrobial agents for potential application in healthcare and beyond.