Synergistic antimicrobial effect of novel heterophase Cu/CuZn/ZnO nanoparticles

Antimicrobial resistance is one of the causes of death worldwide. The gold standard of antimicrobial nanoparticles is silver, but recent studies have demonstrated its cytotoxicity. Since copper and zinc are vital trace elements for human cells, in this study, we synthesized copper/zinc nanoparticles containing beta brass, zinc oxide and copper phases by electrical explosion of two twisted wires. The nanoparticles had an average size of about 100 nm and positive zeta potential in aqueous medium. Such nanoparticles were more effective against a wide range of strains. We showed that depending on the bacterial strain, the antibacterial effect of Cu/CuZn/ZnO NPs was up to ten times higher than that of individual copper and zinc NPs. We also studied the mechanism of action of the nanoparticles and showed that the main mechanisms of synergy are positive surface charge, production of reactive oxygen species and production of copper ions. Antibacterial synergism of copper/zinc NPs can be used to solve medical problems such as the treatment of infected wounds and the elimination of infection during implant placement.