Facile synthesis, characterization of nano-tungsten trioxide decorated with silver nanoparticles and their antibacterial activity against water-borne gram-negative pathogens

In the present work, silver decorated tungsten trioxide (WO3) metal-oxide semiconducting nanoparticles were synthesized using a facile wet impregnation technique for inactivation of harmful water-borne gram-negative pathogens. The structural and morphological properties of self-synthesized pure WO3 nanoparticles (n-WO3) and different weight percentage of Ag metal (3 and 5%) loaded WO3 (3% n-Ag/WO3, 5% n-Ag/WO3) were analyzed by XRD, SEM, TEM and SAED. The loading of Ag on n-WO3 was confirmed by TEM and SAED analysis. The chemical composition of as-synthesized n-WO3, 3% n-Ag/WO3 and 5% n-Ag/WO3 was identified by XPS. The antibacterial characterization and morphogenic studies were done on the following water borne bacteria: Shigella flexneri, Salmonella cholerasis and Escherichia coli. Morphogenesis by electron microscopy revealed the close contact of nanomaterials with the bacterial cell wall and membrane leading to severe damage to the integrity of membrane which caused cell death.