Green Synthesis of Silver Nanoparticles Using Chenopodium aristatum L. Stem Extract and Their Catalytic/Antibacterial Activities

Abstract

Compared with cultivated plants, wild weeds are cheaper and wider available for phytogenetic synthesis of nanoparticles. It is very valuable to distinguish the weed species from the local dominant wild plants for both efficient synthesis of nanoparticles and real industrial applications. In this study, a cheap, simple and novel biosynthesis method for silver nanoparticles (AgNPs) using Chenopodium aristatum. L stem extract as reducing and capping agents was developed. The real-time formation of AgNPs was monitored by UV–vis spectroscopy, and the SPR band was located at ~440 nm. The reaction factors including incubation time, AgNO3 concentration, reaction temperature and pH were discussed and optimized. The synthesized AgNPs were quasi-spherical with the sizes from 3 to 36 nm. HRTEM images and XRD patterns showed that the AgNPs were with the face-centered cubic (fcc) structure. FTIR spectra indicated that some functional groups such like O–H, N–H, C–H, C=O were possibly responsible for reducing silver ions into nanoparticles and acted as capping agents to avoid agglomeration. The synthesized AgNPs exhibited strong catalytic activity in degradation of 4-nitrophenol and good antibacterial activity against E. coli and S. aureus. The proposed phytogenetic synthesis method is economical, simple and feasible.