INTERACTION BETWEEN POLYMERIC ORGANOSILAN E MONOLAYER AND PLASMA-PROTEIN

The n-octadecyltrichtorosilane (OTS) and the [2-(perfluorooctyl)ethyl] trichlorosilane (FOETS) monolayers, and their mixed monolayer were us ed as the model systems for the study of protein adsorption behavior b ecause of their remarkable surface stability. The attenuated total ref lection infrared (ATR-FT-IR) flow cell studies revealed that the adsor ption amount of bovine serum albumin (BSA) onto each OTS and POETS mon olayer steeply increased in an initial stage of adsorption experiment and attained an equilibrium within a few minutes at pH 7.5. In the cas e of the (OTS/POETS) (50/50 mol/mol) mixed monolayer, the amount of pr otein adsorption was suppressed. AFM observation in a BSA solution at pH 7.5 revealed that BSA was preferentially adsorbed onto the POETS ph ase of the (OTS/FOETS) mixed monolayer, while selective adsorption of BSA onto the POETS phase was not observed at the isoelectric point of BSA (pH 4.7). Furthermore, [(3-mercaptopropyl)trimethoxysilane (MTS)/F OETS] mixed monolayer with reactive-SH group in domain was prepared. T hen, the BSA was selectively immobilized onto the MTS phase.