Green synthesis of silver nanoparticles from Valeriana jatamansi shoots extract and its antimicrobial activity

Abstract

The present study explores the potential of Valeriana jatamansi shoot extract for Ag-metal bio-reduction and its antimicrobial activity. Among the different ratios of AgNO3 and extract tested, 1:5 (1 mL AgNO3 and 5 mL extract) gave maximum SPR peak at 411.0 nm during UV-Vis spectrophotometric analysis, indicating the synthesis of maximum amount of AgNPs in solution. XRD analysis reported the crystalline nature of AgNPs with 13.32 nm nanocrystallite size. FTIR studies suggested the involvement of carboxylic acid (-[C-O-O-H]) and methane (-CH-) functional groups of different compounds in AgNPs reduction and fabrication. Average size of synthesized uniform shaped nanospheres was 32 nm by SEM image analysis. The produced AgNPs (1.5 mg/disc) showed growth inhibition of 71.46, 65.97, 61.5, 55.32, and 54.83% against Pseudomonas aeruginosa, Escherichia coli, Candida albicans, Xanthomonas campestris, and Staphylococcus aureus. While the least growth inhibition of 48.55% was recorded for Klebsiella pneumonia, suggesting it as the least-susceptible microbe among all the tested microbial species. P. aeruginosa was found to be most sensitive of all tested microbes, while E. coli, C. albicans, and X. campestris reported moderate susceptibility to AgNPs.