Biological synthesis and characterization of silver nanoparticles using Eclipta alba leaf extract and evaluation of its cytotoxic and antimicrobial potential

With increasing global competitions there is a growing need to develop environmentally benevolent nanoparticles without the use of toxic chemicals. The biosynthesis of silver nanoparticles (AgNPs) using plant extracts became one of the potential areas of research. The bioreduction of metal ion is quite rapid, readily perform at room temperature and easily scale up. The present study describes a rapid and eco-friendly synthesis of AgNPs using Eclipta alba plant extract in a single pot process. The efficiency and the influence of various process variables in the biosynthesis of AgNPs analysed include redundant concentration, temperature and time. AgNPs were rapidly synthesized using aqueous leaf extract of E. alba and was observed when the medium turned to brown colour with the addition of silver ion. Biosynthesized AgNPs were characterized by the help of UV–visible spectroscopy for their stability and physicochemical parameters were studied by dynamic light scattering, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy. The obtained results confirmed that recorded UV spectra show the characteristic surface plasmon resonance band for AgNPs in the range of 400–440 nm and physiochemical structural analysis shown that obtained AgNPs were crystalline in nature. Further, cytotoxic and antimicrobial activities of biosynthesized AgNPs against RAW 254.7, MCF-7 and Caco-2 cells as well as Gram positive and Gram negative bacteria were assessed. In-vitro cytotoxicity activity of characterized AgNPs against tested cell lines showed significant anti-cell-proliferation effect in nanomolar concentrations. The antibacterial activity of synthesized AgNPs showed effective inhibitory activity against human pathogens, including, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Thus, the significant outcome of this study would help to formulate value added herbal-based nano-materials in biomedical and nanotechnology industries.