Antibacterial activity of copper nanoparticles

Copper nanoparticles (CuNPs), with an average particle size of about 5 nm, was prepared by the simple chemical reduction procedure. TEM and UV– Vis spectroscopy contributed to the analysis of size and optical properties of CuNPs, and their antibacterial activity was evaluated toward human pathogenic bacteria Escherichia coli and Staphylococcus aureus, in a concentration dependent manner. The changes in the cell membrane morphology of tested strains were investigated by atomic force microscope (AFM), after 2 h of their contact with CuNPs. It was found that CuNPs cause different types of cell membrane disruptions, as well as that S. aureus bacteria were slightly resistant to the cell membrane damage than E. coli