Tatyana A. Voeikova
National Research Center Kurchatov Institute, Russia
Title: Functional nanoparticles of cadmium sulfide mediated by bacteria
Biography
Biography: Tatyana A. Voeikova
Abstract
Cadmium sulfide nanoparticles were obtained using cells of the bacterium Bacillus subtilis 168 (NPsCdS/Bacillus) in the presence salts of CdCl2 and Na2S. Biogenic NPs are characterized as spherical nanocrystalline structures with a size of 5-6 nm and a zeta potential of -27 mV. The flagellin protein of the Bacillus bacterium was identified on the NPsCdS/Bacillus surface, which forms a significant stabilizing protein coating. The hydrodynamic diameter of the NPs is up to 550 nm. The ability of NPs to fluorescence in the range of 300-450 nm at λex 270 nm is shown. Effective immobilization of NPs on various polymer carriers – aminated chloromethylated polystyrene and amino-containing polyglycidyl methacrylate microspheres, polyimide was carried out. The stability of modified polymer nanocomposites with preservation of NPs fluorescence is shown [1, 2]. The biocidal activity of NPs was established against nine test cultures of microorganisms, including strains of the genera Bacillus, Streptococcus, Enterococcus, Rhodococcus, Pseudomonas, Candida, Saccharomyces. Gram-positive bacteria and yeast showed the greatest sensitivity to NPs. The possibility of using biogenic NPsCdS as photocatalysts for discoloration of dyes of various chemical families in the presence of UV irradiation is shown. The photocatalytic activity of NPs was tested against synthetic organic dyes belonging to the families of thiazine, triphenylmethane and azodyes. The efficiency of photocatalytic discoloration is highest for dyes dyes of the triphenylmethane family and is ~85%. The possibility of triple effective use of NPsCdS/Bacillus for discoloration of a number of dyes is shown. Thus, functional NPsCdS/Bacillus stabilized by a protein coating of bacterial origin were obtained by microbial synthesis, which can serve as an alternative "green" method for obtaining nanomaterials [3] and provides their use for modifying polymer nanocomposite materials, creating antibacterial agents [4] and photocatalysts of a new generation [5].