Biosynthesis, characterisation and antibacterial activity of Mikania micrantha leaf extract-mediated AgNPs

Abstract

In the present years, nanobiotechnology has to turn out to be an important division of research. Here, this work reported a novel Mikania micrantha leaf extract-mediated silver nanoparticle (AgNP) under room temperature condition. The biosynthesised AgNPs were further characterised by various analysis techniques such as ultraviolet–visible spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscope (TEM) energy-dispersive X-ray spectroscopy. The formation of AgNPs was confirmed by XRD spectrum which displayed intense peaks corresponding to the (1 1 1), (2 0 0), (2 2 0) and (3 1 1) lattice planes of Ag. The plant extracts stirred with Ag nitrate solution gradually changes its colour from light yellow to dark brown. The biogenic AgNPs were mostly spherical in shape with varying sizes ranging from 5 to 20 nm, as evident by TEM analysis. FT-IR spectra of the extract revealed the presence of amide I and amide II bonds of the proteins. The synthesised AgNPs showed excellent activity results against various Gram-positive and Gram-negative bacterial strains.