Biosynthesis of silver nanoparticles using Plumbago auriculata leaf and calyx extracts and evaluation of their antimicrobial activities

Karishma Singh, Yougasphree Naidoo, Chunderika Mocktar and Himansu Baijnath

Abstract

The use of plants in the biosynthesis of nanoparticles is a fast-growing technique and has gained much interest from researchers over the years. This study reports the utilization of leaf and calyx extracts of Plumbago auriculata for the biosynthesis of silver nanoparticles (AgNPs). The formation of AgNPs which was confirmed by the colour change in the plant extracts was characterized by UV-Vis spectrophotometric, TEM, SEM, EDX and FT-IR analyses. The water-soluble components of the extracts were responsible for the reduction of Ag⁺ ions. FT-IR analysis revealed the efficient capping and stabilization properties of these particles and the nature of the capping agent. The antibacterial properties of the biosynthesized AgNPs were evaluated against both gram-negative and gram-positive bacteria and the results obtained showed good antibacterial activity against Klebsiella pneumoniae. This was the first reported study for Plumbago auriculataand contributes to the environmentally friendly and cost-effective technique of the biosynthesis of nanoparticles for drug development