Mixed systems based on aminated and sulfonated silica nanoparticles: synthesis, self-assembly, and selective adsorption of certain biopolymers

Abstract

Hybrid aminated and sulfonated nanoparticles were synthesized by surface modification of silica nanopowder with 3-aminopropyltriethoxysilane and 1,3-propanesultone, respectively. The developed protocols for the synthesis of three types of "buffer" mixed submicron particles with corresponding ζ-potentials (–21.4±1.3, 4.7±0.4, 12.4±0.8) were based on various methods of nanoprecipitation of synthesized silica nanoparticles modified by amino- and sulfonate groups, and on various conditions of these precepitation (solvent, temperature). Hybrid SiO₂ particles, as well as self-assembling associates based on sulfonated and aminated particles, were examined in extraction of biologically important macromolecules. It was established that the efficiency of adsorption of calf thymus DNA increased with increasing zeta potentials of the modified silica particles studied. The interaction of the studied model proteins (bovine serum albumin and lysozyme) with the synthesized silica nanoparticles modified by sulfonate groups increased as the pH of the medium decreased.