Eco‐Friendly Synthesis of Silver Nanoparticles Using <i>Sapindus mukorossi</i> Extract With Antibacterial and Photocatalytic Activities

Green synthesis of silver nanoparticles (AgNPs) offers an eco‐friendly approach for developing multifunctional nanomaterials. In this study, AgNPs were synthesized using Sapindus mukorossi fruit extract as both reducing and stabilizing agents. UV–visible spectroscopy showed a characteristic surface plasmon resonance peak at ∼430 nm, while X‐ray diffraction confirmed their crystalline nature. Fourier‐transform infrared spectroscopy revealed the involvement of phytochemicals in nanoparticle formation. Analysis of 200 nanoparticles by TEM revealed a unimodal size distribution (5.12–59.89 nm) with an average diameter of 30.32 nm; over 80% of particles were between 10 and 50 nm. The AgNPs demonstrated broad‐spectrum antimicrobial activity, as evidenced by agar well diffusion assays against Staphylococcus aureus (including clinical isolates) and Salmonella enterica . Inhibition zones ranged from 11 to 16 mm for S. aureus and averaged 20 mm for S. enterica , highlighting their efficacy against both Gram‐positive and Gram‐negative bacteria. The antibacterial activity was retained when AgNPs were stored in 100% DMSO for up to 1 month, indicating good long‐term stability. Additionally, the AgNPs demonstrated effective photocatalytic degradation of Congo red dye under halogen light in the presence of NaBH 4 . These results underscore the potential of S. mukorossi –mediated AgNPs as stable, broad‐spectrum antibacterial agents with applicability in biomedical and environmental remediation.