Antibacterial potential of silver nanoparticles synthesised by electron beam irradiation

Abstract

Antibacterial activity of silver nanoparticles synthesised by irradiating an aqueous solution of AgNO3 in a bio-compatible polymer polyvinyl alcohol (PVA) with electrons from a microtron, at doses of 1 kGy and 2 kGy, has been evaluated against selected Gram-positive and Gram-negative bacteria. Nanoparticles produced by electron beam irradiation (EBI) at 1 kGy showed significantly higher inhibitory effects than 2 kGy on Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus and Streptococcus pneumoniae). The inhibition was highest on P. aeruginosa, while it was least on S. aureus. The particles generated at 1 kGy at 1,000 μg/ml concentration showed significantly lower number of colonies of P. aeruginosa against 100 μg/ml. Our study demonstrates that silver nanoparticles generated at 1 kGy irradiation dosage will be of immense value to produce broad spectrum bacteriostatic or bactericidal agents and needs further studies for clinical applications.