Pectin-stabilized silver nanoparticles: synthesis, optical and antimicrobial activity against E. Coli

Nanoparticles synthesis using biomaterials is gaining popularity due to their biocompatibility, green approach and environmentally friendly nature. In this study, we report for the first time a simple and rapid synthesis of silver nanoparticles (AgNPs) via a one-step green approach using pectin obtained from the pulp of Parkia biglobosa as a novel reducing and stabilizing agent, which can serve as sustainable and economically viable alternative to conventional synthesis. The synthesized nanoparticles were characterized using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), UV–Visible Spectrophotometer, Fourier Transform Infra-Red (FTIR) and Energy Dispersive X-ray Fluorescence (EDXRF) Spectroscopy. Different factors affecting AgNPs synthesis were studied by varying the volume of pectin solution, concentration of silver nitrate (AgNO3) and pH of the reaction. Optimum conditions for the synthesis of AgNPs were found to be at a pH of 12, 10 mM AgNO3 concentration and 3 mL pectin solution. Photoluminescence study showed that AgNPs formation began within 5 min of the reaction time under sunlight. Analysis of SEM and TEM suggested the formation of well dispersed silver nanoparticles with average particle size within 20–30 nm. The AgNPs showed antibacterial activities against Escherichia coli. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) were found to be 50 and 100 µg/mL respectively. The study indicates that AgNPs synthesized using pectin from P. biglobosa exhibit great potential for applications in biomedicine, catalysis, bioremediation and food preservation.