GREEN SYNTHESIS OF SILVER NANOPARTICLES FROM AQUEOUS EXTRACT OF STEMODIA VISCOSA AND ITS EVALUATION OF ANTIMICROBIAL ACTIVITY

Karthigaiselvi K. and Sudha Rameshwari K.*

ABSTRACT

Silver nanoparticles are prepared from aqueous extract of Stemodia viscosa. The silver nanoparticles (AgNPs) were characterized by UV-Visible spectrometer. The synthesized silver nanoparticles were subjected to phytochemical screening and these particles were tested against selected clinical pathogens [E.coli, Staphylococcus aureus, Pseudomonas aeruginosa, Shigella flexneri, and Pseudomonas fluorescence]. The aqueous leaf extract of Stemodia viscosa was pale yellow in colour, and after the addition of aqueous silver nitrate, the colourless to honey brown within the 1 hours. It indicates the formation of silver nanoparticles. The UV- Vis analysis from 400-800 nm revealed that maximum absorbance. UV-Vis spectra of synthesized AgNPs, which give a sharp band at around 500 nm confirmed the presence of nanoparticles. The results of antimicrobial activity revealed that the AgNPs of Stemodia viscosa was found to be most effective against S.aureus with 27 mm in diameter, followed by P. aeruginosa with 25mm in diameter. From the above results, it was found out that AgNPs of Stemodia viscosa exhibit a remarkable antimicrobial activity. Hence, AgNPs of Stemodia viscosa can be used for the treatment of various diseases. This study suggests that this plant is used for the development of antimicrobial drug.

Keywords: Stemodia viscosa, silver nanoparticle, gram positive and gram negative bacteria.