Photoinduced green synthesis of silver nanoparticles using aqueous extract of Physalis angulata and its antibacterial and antioxidant activity

Abstract

The present work discusses the establishment of green route for the rapid synthesis of silver nanoparticles (AgNPs) using aqueous extract of Physalis angulata (AEP) leaves which act as a reducing as well as a capping agent. The change in color from watery to dark brown confirmed the synthesis of AgNPs. A characteristic surface plasmon resonance (SPR) band at 436nm advocated the presence of AgNPs. The synthesis process was optimized using one factor at a time approach where 2.0mmolL−1 AgNO3 concentration, 4.5% (v/v) of AEP inoculum dose and 10min of sunlight exposure were found to be the optimum conditions. The synthesized AgNPs was characterized by several characterizing techniques such as Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Atomic Force Microscopy (AFM) analysis. The synthesized AgNPs showed strong antibacterial activity against both Gram-negative and Gram-positive bacteria as well as antioxidant activity. Herein, an effort was also made to propose the mechanism of biosynthesis, antibacterial activity as well as antioxidant activity.