Green synthesis of silver nanoparticles using vinca roseus leaf extract and evaluation of their antimicrobial activities.

ABSTRACT

In the present study, silver nanoparticles were rapidly green synthesized from AgNO3 solution using leaf extract of Vinca Roseus at room temperature. The green synthesized Silver Nanoparticles were characterized by UV–Visible absorption spectroscopy and further by analytical techniques such as, DLS, X-ray diffraction (XRD) and SEM. X-ray diffraction and Scanning Electron Microscope analysis studies confirmed the formation of welldispersed silver nanoparticles with average particle size to be in the range of 20-80 nm as well as revealed their cubic structure. Further these green synthesized silver nanoparticles were evaluated for their antimicrobial activities against different pathogenic bacteria like Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus by using Disc - diffusion methods and the bacterial growth kinetics. The activity was monitored by measurement of zone of inhibition and optical density (OD). The results evaluated that the antimicrobial activity of green synthesized silver nanoparticles was higher against gram - positive bacteria compared to gram-negative bacteria.