Biosynthesis of silver nanoparticles using Pergularia daemia (Hamilton, 1822) leaf extract and its enhanced antibacterial activity against gram negative bacteria (Escherichia coli)

Abstract

The present study describes the antibacterial activity of silver nanoparticles synthesized using leaf extracts of Pergularia daemia (Hamilton, 1822). Initially, the synthesis of AgNPs was confirmed by visual observation as colour change from light yellow to brown colour. Further, the morphology of the biosynthesized nanoparticles, average size and presence of elemental silver were characterized by UV – Visible spectroscopy, X - ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Field Emission Scanning Electron Microscope(FE-SEM). The UV spectra results show a strong resonance centre and surface of silver nanoparticles (AgNPs) at 420 nm. XRD studies revealed that the synthesized AgNPs shows spherical in shape. The FT-IR spectrum described the biological molecules which perform dual functions of stabilization and formation of silver nanoparticles in the aqueous medium. FE-SEM image shows a size distribution of nanoparticles size range 30–45 nm. In vitro antibacterial effect of various concentrations of AgNPs was investigated against Gram negative bacterial strain. The antimicrobial property of AgNPs was tested against Gram negative (Escherichia coli) pathogen, which showed zones of inhibition at different concentrations. The result shows that biosynthesized AgNPs have significant antibacterial activity.