Antibacterial Activity of Copper Nanoparticles and Copper Nanocomposites against Escherichia Coli Bacteria

Nanotechnology is an emerging technology which has wide applications in many fields. The major objective of the study is to synthesise copper nanoparticles and its composites and to determine their antibacterial activity. A filter based on the developed material was fabricated. Copper nanoparticles were synthesised by chemical reduction method and were encapsulated in a biopolymer, alginate and fabricated anti bacterial water filter using copper nanoparticle-coated polyurethane foams. The synthesised copper nanoparticle, copper nanoparticle encapsulated in alginate beads and copper nanoparticle coated PU foam were characterized by several techniques including SEM and EDS analysis. Finally antimicrobial efficiency was determined against E.coli. Well diffusion method was used for testing the antibacterial effect of synthesised nanoparticls. The time and dose dependant study of copper alginate beads showed that the effectiveness of particle increase with increasing particle dose and contact time. The results obtained from the effect of bacterial load indicated that there was a decrease in antibacterial activity as the bacterial concentration increased. Flow test was conducted for the antibacterial filter by passing contaminated water through the filter and no bacteria were detected. The antimicrobial activity of metal nanoparticles is due to the large surface area which ensures a broad range of reactions with bio-organics present on the cell surface. Our research suggests that copper-coated polyurethane foams can be used as excellent antibacterial water filter.