The effect of Cu and Cuo nanoparticles covered with surfactant on the viability of Escherichia coli

Abstract

Nanoparticles, which distinguish themselves with antibacterial properties, are a lot discussed during two last decades. Nanoparticles can be found in different forms, sizes which range in 1 to 100 nm, compositions and charges, which cause different effect on bacteria viability. In our study we chose Cu and CuO nanoparticles, where our aim was to evaluate the antibacterial activity of investigated nanoparticles on Escherichia coli bacteria. Nanoparticles passages in to the cell depend on their size and coating, therefore we used 25 – 60 nm size nanoparticles. Sodium cholate (NC) is surfactant from bile salts, used to stop aggregation and stabilize nanoparticles. (Lin, Blankschtein, 2010). NC is anionic surfactant, widely used as absorption enhancer to maximize transport of substances into cell (Senel, Hincan, 2001). Concentration of NC in humans depend on its location – in duodenal it is 20 nm, in bile – 14 mM. (Moghimipour et al., 2015). In our study we used 20 mM and lower concentrations solutions of NC for the coating of nanoparticles. Surface tension method was used to determine critical micelle concentration (CMC) of surfactant solution. Bacteria viability was evaluated by 96 well-plates spectrophotometric method. The effect of polar CuO nanoparticles on viability of E. coli bacteria was higher compared with Cu nanoparticles. The same effect was noticed when nanoparticles were coated with sodium cholate. Viability of bacteria which were coated with sodium cholate was decreased almost two times compared with noncoated bacteria.