The development of a reliable, cost effective and environmentally-friendly technique for the biogenic synthesis of nanomaterials is an important aspect of current nanotechnology research. In the present attempt, we describe biogenic synthesis of silver nanoparticles (AgNPs) from 1mM AgNO3 solution using E. coli strain. The bio-based silver nanoparticles in the reaction mixture appeared brown coloration. Nanoparticles were characterized using UV–Vis spectroscopy, X-ray diffraction (XRD) and Scanning electron microscopy (SEM) analysis. The nanoparticles showed maximum absorbance at 420 nm on ultraviolet-visible spectra. The average size of the nanoparticle was 26.25 ± 13.10 nm. The energy-dispersive spectroscopy (EDS) of the nanoparticles confirmed the presence of elemental silver. No other signal peaks of impurity were detected. Silver nanoparticles exhibited high antibacterial activity using Staphylococcus aureus as an indicator strain. Bacterial killing kinetics in the presence of fabricated silver nanoparticles exhibited higher killing rate against Staphylococcus aureus (94.8%). The correlation coefficient between silver nanoparticles and selected bacterial pathogens revealed that there is a strong negative correlation with (r = -0.83 to -0.99)
