Features of Silver Sulfide Nanoparticles Bacterial Synthesis: Molecular Modeling

Abstract

Molecular mechanisms of a promising material for nanoelectronics -silver sulfide nanoparticles- bacterial synthesis are studied using quantum chemical modeling methods. The peculiarity of obtaining silver sulfide nanoparticles by biosynthesis using bacteria Bacillus subtilis 168 is that the only flagellin protein involved in the synthesis process and adsorbed on the surface of the particles. Investigated objects are salts-silver nitrate and sodium thiosulfate, which are involved in the synthesis process, and non-standard amino acid methyllysine as a part of flagellin. The study was based on of molecular structures and IR spectra calculation using density functional theory by the Gaussian 09 software package and on analysis of formed hydrogen bonds parameters. It was discovered that methyllysine forms a sufficiently stable molecular complexes with silver nitrate and sodium thiosulfate. This makes it possible to talk about the significant role of methyllysine in the formation of silver sulfide nanoparticles and clarifies the mechanism of its functioning as a part of flagellin.