Green synthesis of silver nanoparticles using Capsicum frutescence and its intensified activity against E. coli

Abstract

The purpose of this study was to expand a trouble free biological method for the synthesis of silver nanoparticles using the fruit extract of Capsicum frutescence (Sweet pepper) to act as reducing and stabilizing agent. Water soluble organics played a vital role for the reduction silver ions into silver nanoparticles. The fruit extract was exposed to silver ions and the resultant biosynthesized silver nanoparticles characterized by UV–Vis spectrophotometry indicated the surface plasmon resonance band at 385–435 nm. X-ray diffraction spectrum showed crystalline structure while scanning electron microscope analyses exposed the monodispersed distribution and particle size of 20–25 nm. The elemental analysis displayed strong signal at 3 keV that agrees to silver ions and confirms the presence of metallic silver. The antibacterial activity of silver nanoparticles was determined by agar well diffusion method against gram positive and gram negative bacteria. Maximum and minimum zones of inhibition were renowned against Escherichia coli (11.5 mm) and Bacillus subtilis (10.5 mm), respectively. This study exposed that silver nanoparticles retained good bactericidal activity at 80 µg/ml concentration.