Comparison of antioxidant, antimicrobial, DNA cleavage, cell viability, and biofilm inhibition activities of mono- and bimetallic copper and zinc nanoparticles

This study reveals the antioxidant, antimicrobial, DNA cleavage, cell viability and biofilm inhibition capacities of copper and zinc mono and bimetallic nanoparticles (NPs). The SEM micrograph and DLS results showed that the morphology and size distribution of NPs were spherical and sub100 nm in size and bimetallic Cu/Zn NPs were also confirmed to be in a core–shell structure by TEM analysis. The biological activity results showed that the highest DPPH scavenging activity was achieved with Zn NP as 65.72 %. Bimetallic Cu/Zn NPs displayed excellent chelating ability as 100 % at 25 mg/L which was higher than standard and Cu and Zn nanoparticles. The antimicrobial activities were evaluated by microdilution procedure. Cu NPs demonstrated significant DNA nuclease activity and the plasmid DNA fragmented into small oligonucleotides. All new synthesized NPs exhibited 100 % cell viability inhibition at 250 mg/L. The effect of synthesized NPs on biofilm inhibition produced by S. aureus and P. aeruginosa was also tested and Zn NP and bimetallic Cu/Zn NPs showed good biofilm inhibition against S. aureus as 68.4 % and 67.36 %, respectively. As a result, Cu and Zn nanoparticles and bimetallic Cu/Zn NPs exhibited excellent biologic activity. The lack of sufficient biological activity studies with bimetallic Cu/Zn nanoparticles in the literature makes this study’s results unique.