Adsorption of Human Plasma Albumin and Fibronectin onto Nanostructured Black Silicon Surfaces

The protein adsorption of two human plasma proteins—albumin (Alb) and fibronectin (Fn)—onto synthetic nanostructured bactericidal material—black silicon (bSi) surfaces (that contain an array of nanopillars) and silicon wafer (nonstructured) surfaces—was investigated. The adsorption behavior of Alb and Fn onto two types of substrata was studied using a combination of complementary analytical techniques. A two-step Alb adsorption mechanism onto the bSi surface has been proposed. At low bulk concentrations (below 40 μg/mL), the Alb preferentially adsorbed at the base of the nanopillars. At higher bulk concentrations, the Alb adsorbed on the top of the nanopillars. In the case of Fn, the protein preferentially adsorbed on the top of the nanopillars, irrespective of its bulk concentration.