Synergetic Antibacterial Activity of CuO-Ag Janus Like Nanoparticles

Abstract

Abstract This work provides a comparative evaluation of the antibacterial activity of CuO-Ag Janus particles and a bicomponent mixture of CuO and Ag particles against a recombinant strain Escherichia coli K12 TG1 with cloned luxCDABE genes of marine bacteria Photobacterium leiognathi 54D10. An original method for the preparation CuO-Ag nanoparticles by simultaneous electrical explosion of twisted Cu and Ag wires in a mixture of argon and oxygen gases was used. The CuO-Ag Janus nanoparticles have been found to be the most bioactive with respect to the studied biosensor, causing 50% inhibition of bioluminescence (EC50 = 0.03 ± 0.001 mg/ml) (p < 0.05). At the same time, an order of magnitude less pronounced inhibitory effect was observed with CuO particles doped with 70 nm silver nanoparticles (EC50 = 0.25 ± 0.002 mg/ml) (p < 0.05). Against this background, the nominal toxicity values of CuO and Ag as monocomponent nanoparticles were 2–32 times lower compared with the bicomponent nanoparticles. A dose-dependent inhibition of bacterial luminescence developed over time was noted. Thus, as a result of the contact of E. coli with CuO-Ag Janus particles, 100% suppression of bacterial luminescence from the first minutes of contact occured, starting with a content of 2.0 mg/ml, and within the next 180 minutes, the effect of bioactivity prolonged in the final concentration of nanopowder (EC100 = 0.0625 ± 0.002 mg/ml) (p < 0.05). CuO-Ag Janus particles exhibit more pronounced antibacterial activity compared to CuO, Ag nanoparticles and their mechanical mixture.