Microbial Synthesis of Cadmium Sulfide Nanoparticles: Influence of Bacteria of Various Species on the Characteristics of Biogenic Nanoparticles

Optimization of an ecologically friendly, biological approach to the microbial synthesis of cadmium sulfide nanoparticles (NPsCdS) in the presence of Shewanella oneidensis MR-1 and Bacillus subtilis 168 bacterial cells is proposed, which increases the yield and concentration of nanocrystals in the samples. Biogenic NPsCdS are characterized as quantum dots with a size of 5 ± 1 nm, fluorescent in the blue region of the spectrum. A comparative assessment of the protein coating composition of biogenic NPsCdS, their hydrodynamic diameter, zeta-potential, and polydispersity was carried out, and the dependence of a number of parameters on the type of bacterium used in biosynthesis was shown. The effect of strains on the absorption spectra of nanoparticles, wavelength, and fluorescence intensity level was studied. The influence of centrifugation and ultrasonic treatment on the electrophoretic and optical properties of biogenic nanoparticles as ways to increase the monodispersity of colloidal systems is considered. The results presented confirm the prospect of applying biogenic NPsCdS along with chemically synthesized nanostructures.