A Novel Biosynthesis, Characterization and Antimicrobial Activity of Silver Nanoparticles Using Leaves Extract of Mentha longifolia

Introduction: In this report, we have investigated a simple, fast and eco-friendly method to synthesize silver nanoparticles (AgNPs) by the process of bio-chemical reaction between silver nitrate (AgNO3) solutions with leaf extract of Mentha langifolia without any hazardous chemicals as reducing or stabilizing agents.Material and methods: Nanoparticles forming were indicated by the color changes in solution from yellow to dark brown and were confirmed by UV-Vis spectrum. The synthesized AgNPs were analyzed by various characterization techniques to reveal their morphology and chemical composition such as FT-IR analysis and Scanning Electron Microscopic (SEM) micrograph. The average particle size of produced AgNPs was determined by dynamic light scattering (DLS) technique. Further, the antibacterial activity of synthesized AgNPs was evaluated against Streptococcus pneumonia and staphylococcus epidermidis as Gram-positive bacteria and Salmonella enterica and enterobacter aerogenes as Gram-negative bacteria. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of biosynthesized silver nanoparticles were determined.Results and conclusion: UV-Visible spectrophotometer showed absorbance peak in 340 nm. SEM images of these AgNPs and DLS analysis indicated the formation of spherical, dispersed nanoparticles of mean size of 21.1 nm. The antibacterial activity of the silver nanoparticles were studied against subject bacteria. The results showed the silver nanoparticles to be effective against the four tested bacterial isolates at 25, 50 and 100 µl concentration. The zone of bacterial inhibition by AgNPs collected from Mentha longifolia leaf extract show maximum inhibition against Streptococcus pneumonia and Enterobacter aerogenes. Thus, present study defines the use of medicinal plant for biosynthesis of AgNPs and its potential use against microbes.

کلیدواژه ها:

Silver nanoparticles ، Mentha longifolia ، Green synthesis ، Antibacterial activity