Synthesis and Antibacterial Activity of Silver Nanoparticles Against Escherichia coli and Pseudomonas sp.

Silver nanoparticles (AgNPs) have been synthesized by chemical reduction method using ascorbic acid as reducing agent. Silver nitrate (AgNO3) and sodium dodecyl sulfate (SDS) have been used as precursor and stabilizer, respectively. The prepared samples were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The antibacterial activity of prepared silver nanoparticles has been assessed by using the disc diffusion method against pathogenic, gram-negative bacterial strains including Escherichia coli and Pseudomonassp. To evaluate the potential antibacterial properties of AgNPs, the discs have been impregnated and dried with three different doses like 50, 100 and 150 mu l of 20 mu g/ml concentrated AgNPs solution and placed on the Petri-dishes. The antibiotic kanamycin (5 mu g) was used as control. In all the cases, a clear and distinct zone of inhibition is observed, which suggests that AgNPs can be used as effective growth inhibitors of various bacterial species and would be promising candidate for future development of antibacterial agents.