Green synthesis and characterisation of <i>Desmodium podocarpum</i> mediated silver nanoparticles and their biological activities

This research explored silver nanoparticles (AgNPs) from <i>Desmodium podocarpum</i> rhizome using the green approach and their possible antibacterial, phytotoxic, and haemolytic activities. The change in the colour from transparent to light brown and finally to colloidal brown indicates the synthesis of nanoparticles. The synthesised AgNPs were analysed by UV–Vis spectrophotometer, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infra-red spectroscopy and energy dispersive X-ray. The analysis indicates the successful reduction of Ag⁺² ions to Ag^o with spherical particle size 16–55 nm. The prepared AgNPs inhibit the growth of <i>Escherichia coli</i>, <i>Salmonella typhi</i>, <i>Staphylococcus aureus</i> and <i>Pseudomonas aeruginosa</i>. It showed 70% phytotoxic potential and 12% haemolysis at high concentrations. Altogether, these results strongly suggest that <i>D. podocarpum-</i>mediated AgNPs could be used eco-friendly to limit microbial growth without any significant cytotoxic effect on human cells.