Characterization and antibacterial response of biosynthesized silver nanoparticles using Eclipta alba (L.) Hassk. leaf extract

A variety of plant extracts have been used for the green synthesis of nanoparticles as they contain bioactive compounds with high metal-ion reducing potential. In this study, we investigated the green synthesis of silver nanoparticles (AgNPs) using leaf extracts of Eclipta alba (L.) Hassk. (Syn. Eclipta postrata (L.), as well as the antibacterial potential of the nanoparticles. Initial indications of AgNPs formation were a change in colour of the reaction mixture; namely, from green to brown, which was further confirmed by a characteristic SPR peak of 320 and 450 nm, respectively, measured by UV-vi s spectroscopy. Scanning electron microscopy (SEM) showed the cuboidal morphology of AgNPs with the size range of 70 to 140 nm. The fourier transform infrared spectroscopy (FT-IR) spectra of AgNPs shows the presence of polyphenols and other plant derived compounds as well as proteins which reduces silver ion to AgNP's. Antimicrobial activity of green synthesized AgNPs against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were studied. Against E. coli and P. aeruginosa, AgNPs showed high antibacterial activity in comparison with S. aureus. In this study, it was demonstrated that eco-friendly green synthesized AgNPs may be more useful in biomedicine, water purification and nanobiotechnology in the near future.