Abstract

Silver nanoparticles are a well-known antimicrobial agent used in disease management and commercial production of biomedicine. Nowadays, biological Synthesis of AgNPs (silver nanoparticles) is a green way to replace conventional chemical methods. In the present study, silver nanoparticles were prepared using the cell-free supernatant of bacterial isolate which was then identified as Enterobacter mori strain C29(1)CG by 16S rRNA molecular sequencing. Based on optical colour shift, the biosynthesized silver nanoparticles were characterized using UV-visible spectroscopy, X-ray diffraction (XRD) pattern, Fourier Transform Infra-Red (FTIR), Scanning electron microscopy (SEM), and EDX analysis. These nanoparticles showed a characteristic absorption peak between 400-500 nm in the UV-visible spectrum. The crystalline nature of AgNPs was estimated by XRD. FTIR reveals the functional group present in the biosynthesized AgNP sample. SEM image and EDX analysis revealed the formation of irregular spherical nanoparticles. Furthermore, the antimicrobial activity of AgNPs was also assessed against three test pathogens-Staphylococcus aureus, Streptococcus mutans and Klebsiella pneumoniae by measuring the inhibition zone. Hereby, the findings revealed that these biosynthesized AgNPs showed maximum zone of inhibition against Staphylococcus aureus and can be considered a powerful antimicrobial agent against pathogenic bacteria.

Key words: Keywords: Biosynthesis; Silver nanoparticles; Antimicrobial activity; Pathogens; Inhibition zone.