No reports are available for mechanism of bactericidal effect of copper nanoparticles, therefore, we speculate the similar mechanism of action of copper nanoparticles, as silver ones. Copper ions released subsequently may bind with DNA molecules and lead to disorder of the helical structure by cross-linking within and between the nucleic acid strands. Copper ions inside bacterial cells also disrupt biochemical processes . However, the exact mechanism behind bactericidal effect of copper nanoparticles is not known and needs to be further studied on the broader range of bacteria strains