Dynamic Surface Properties of Solutions of Bovine Serum Albumin Complexes with Silica Nanoparticles

Abstract

Surface properties of aqueous dispersions of bovine serum albumin complexes with silica nanoparticles have been studied using a set of methods that are sensitive to changes in the structure and composition of surface layers. In spite of the similar charges of the components, their interaction leads to changes in the surface properties of the dispersions; namely, the rates of variations in the dynamic surface elasticity and dynamic surface tension decrease due to the high electrostatic barrier of adsorption. The addition of an electrolyte decreases the electrostatic barrier. In this case, the adsorption of the complexes leads to a growth in the dynamic surface elasticity from the values characteristic of pure bovine serum albumin solutions (~80 mN/m) to 170 mN/m, which corresponds to the formation of macroscopically homogeneous adsorption film of nanoparticle–protein complexes.