One-Pot Electrical Explosion Synthesis of Heterophase CuO/Cu2O/Ag Nanoparticles as a Perspective Antimicrobial Agent

Abstract

Obtaining new materials with antibacterial activity is an urgent task due to the emergence and proliferation of new antibiotic resistant strains, as well as the increasing requirements for the effectiveness and toxicity of such materials. Electrical explosion of two twisted wires (EETW) to produce of heterophase nanoparticles is attractive for develop novel antibacterial agents. Our work describes simple and environmental friendly way to obtain novel composite CuO/Cu₂O/Ag nanoparticles with different silver mass ratio (15, 50, 90%) by the simultaneous electrical explosion of Ag and Cu twisted wires in oxygen containing atmosphere. The using of EETW for the production of heterophase NPs is due to several advantages such as high purity of nanoparticles, good productivity (about 120 g nanoparticles per hour) and eco-friendliness. The obtained nanoparticles have irregular spherical shape morphology. According to EDX analysis dates, the nanoparticles have Janus-like structure, where one part is enriched with Ag and the other with Cu and O. The mean particle size depended on silver content and was 63 ± 2 nm (90% Ag), 92 ± 2 nm (15% Ag). CuO/Cu₂O/(50)Ag particle size distribution have two peaks, one at 35 ± 1 nm and the other at 79 ± 2 nm. The NP zeta potential of nanoparticles measured neutral pH and 25 °C was positive (more than 20 mV). CuO/Cu₂O/Ag nanoparticles with 50% Ag significantly inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA) with MIC = 62 µg/mL. The antibacterial activity nanoparticles with 90%Ag determined by the disco-diffusion method was slightly lower than that of the nanoparticles with 15 and 50% Ag. The possible antibacterial mechanisms may be attributed to the synergistic effect of the heterostructure of EETW nanoparticles and the formation of galvanic nanopairs. The presence of silver metal and copper oxides in nanoparticles can promote galvanic corrosion, leading to the release of more metal ions into the bacterial suspension. We have shown that the nanoparticles obtained have a positive zeta potential, unlike Ag nanoparticles, which may contribute to a better adhesion of nanoparticles to the surface of bacterial cells. The synthesized NPs have broad potential to be developed in pharmaceutics as an effective antimicrobial nanomaterial.