Directional Sensing of Protein Adsorption on Titanium with a Light-Induced Periodic Structure

Abstract

Directional dependence of adsorbed human plasma fibrinogen (HPF) and human serum albumin (HSA) on highly ordered pyrolytic graphite (HOPG), on polished titanium (Tip), and on titanium with a light-induced periodic surface structure (TiLIPSS) was investigated. Analyses, in the temporal domain, were conducted with a diffractive optical element (DOE)-based sensor that senses both topography (optical roughness) and reflectance related (gloss) parameters of the biomolecule-covered surface in phosphate buffered saline. Optical analysis was conducted from data measured with DOE in vitro. During the measurements, the probing laser beam had three different angular directions of the electric field of photons to inspect the directional responses from the studied surface types. First, results showed that the HOPG was found to be statistically inert for the measured biomolecule HPF adsorption, but with HSA, it was found to be adsorbed onto the HOPG surface. The Tip and TiLIPSS showed a more reactive adsorption process...