Green synthesis of silver nanoparticles through reduction with Euphorbia nivulia Buch.-Ham., stem bark extract: Characterization and antimicrobial activity

Nanoparticles, because of their diversified applications in the field of modern medicine, have gained a lot of importance thrust area. In the present investigation, synthesis and characterization of Silver nanoparticles (AgNPs) and their antimicrobial effect on certain pathogenic bacteria were studied. AgNPs were prepared by green synthesis process using stem extract of Euphorbia nivulia, from 1 mM AgNO3 solution. The color change was observed after the addition of AgNO3 due to the surface plasmon vibration. The detailed characterization of the nanoparticles was carried out using UV-Vis spectrometry at 400 to 700 nm; maximum absorption peak was observed at 432 nm. FTIR analysis showed the functional groups involved in the AgNPs formation. Scanning Electron Microscopy (SEM) revealed the structure and the size of nanoparticles spherical and 20-90 nm respectively. The antimicrobial activity screened for eight bacterial strains and one fungal strain. AgNPs showed highest inhibition (33.5±0.5) against Escherichia coli, followed by Pseudomonas aeruginosa (30.5 ±0.5), Bacillus subtilis  (29 ±1) Salmonella typhimurium (28±1), Bacillus cereus (27±1) Staphylococcus aureus (24.5 ±1.5) and  Klebsiella pneumoniae (23.5 ±0.5) and one fungal strain Candida albicans (26±1). Key words: Euphorbia nivulia, stem bark, silver nanoparticles, characterization, antimicrobial activity.