Biosynthesis of silver nanoparticles using salvia officinalis extract and assessment of their antibacterial activity

Recently, the biosynthesis of nanoparticles has been considered as a new approach of research. In the current investigation, the green chemistry of silver nanoparticles synthesis from aqueous solution of silver nitrate as a rapid eco-friendly technique was described. Extracellular biosynthesis of silver nanoparticles (AgNPs) was carried out using plant extracts of Salvia officinalis L. The AgNPsformation was detected by the colour change of plant extracts and confirmed with the help of UV-Vis spectroscopy where the peak values were in the range of 425– 445 nm. In this study, bio-synthesized AgNPsas well as the ethanolic extract of S.officinalis were tested for their antibacterial activity using a well diffusion method against some bacterial species; Pseudomonas aeruginosa (Gram negative) and Gram positive bacteria (Bacillus subtilis, Streptococcus faecalis and Staphyllococcusaureus). Results from this investigation showed that AgNPs mediated by S. officinalis had an inhibition zone diameter ranging between (3.4 – 9.5 mm). Inhibition zone ranged (11.1 – 16 mm) was observed effect for S. officinalis leaves extracted with ethanol. Furthermore, MIC (Minimum Inhibitory Concentration and MBC (Minimum Bactericidal Concentration) were also determined for the ethanolic leaves extract. The MIC was 25 mg ml and the MBC was 50 mg/ml. The observed differences among the bactericidal activities against the tested organisms might be attributed to the microbe characteristics. Our findings indicated that AgNPs synthesis mediated by S. officinalis extracts had an efficient bactericidal activity. Future investigations are required to perform experiments to explore the unknown mechanism for the bactericidal activity of biogenic AgNPs.