Silver nanoparticles embedded into silica functionalized with vitamins as biological active materials.

The paper describes a rapid and simple method for preparing silver nanoparticles coated with tunable silica shell thickness and their further functionalization with vitamins. Monodispersed silver nanoparticles (Ag NPs) with a mean particle size of 10 nm were prepared by chemical reduction. Silica coating was carried out using the Stober method, by mixing the as prepared silver nanoparticles with tetramethoxysilane and 3-aminopropyltrimethoxysilane. These core–shell nanoparticles were further functionalized with B vitamins in order to facilitate their rapid functionalization to a wide range of end applications. Characterization of the newly synthesized materials was made by UV–visible absorption spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS) and thermal analysis (TG). Their antibacterial activity against Gram-positive and Gram-negative bacterial strains was investigated and the results of our study showed that the linked vitamins on silver nanoparticles coated with silica lead to an increased antimicrobial activity at lower concentrations against planktonic bacterial cells and microbial biofilms. The present study can be useful for future development of different types of biological active materials. [ABSTRACT FROM AUTHOR]