Synthesis, Characterization and Antibacterial Activity Studies of Eco-Friendly Silver Nanoparticles from the Leaf Extract of Jatropha Curcas

Abstract

Production of environmentally amenable silver nanoparticles (AgNPs) has earned the interest of the scientific community owing to their broad applications, primarily in the field of optronics, sensing, and extensively in pharmaceuticals as promising antioxidant, antimicrobial and anticancer agents. Conventionally silver nanoparticles are synthesized by a chemical method using chemicals as reducing agents which later become accountable for various biological risks due to their general toxicity; engendering the serious concern to develop environment-friendly processes. This study explored the production of eco-friendly AgNPs and the investigation of their antibacterial activity using ethanolic leaf extract of Jatropha curcas (LEJC) as the reducing agent and aqueous silver nitrate as the precursor. The characteristics of the synthesized LEJC-AgNPs were studied by ultraviolet-visible spectroscopy (UV-Vis), Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). The LEJC-AgNPs formation was observed from the colour change of the mixture from dark-yellow to colloidal brown. A distinctive absorption maximum with surface Plasmon resonance at 425 nm confirmed the formation of LEJC-AgNPs and data on SEM analysis have shown that the synthesized nanoparticles were in the nano range and predominantly irregular and spherical in shape. FTIR identified the functional groups present in the extract for the formation of the LEJC-AgNPs. This green synthesis provides an economic, eco-friendly, and clean synthetic route to AgNPs. The assessed antibacterial activity of the LEJC-AgNPs obtained depicts activity against Staphylococcus aureus (Gram-positive), Escherichia coli and Klebsiella Pneumonia (Gram-negative) at 20, 40, and 80 mg/mL respectively. This data is reflective of the role of LEJC-AgNPs as a potential and promising antimicrobial agent against bacterial infections.