Chemical Vapor Deposition of Poly(hydroxyethyl methacrylateglycidyl methacrylate) Thin Film Coatings for Immobilization of Human Serum Albumin

Abstract

In this study, poly(2-hydroxyethyl methacrylate-glycidyl methacrylate) (P(HEMA-GMA) thin films were deposited on crosslinked polyvinyl alcohol (PVA) supports by initiated chemical vapor deposition (iCVD). Use of the tert-butyl peroxide as an initiator allowed very high deposition rates up to 125 nm/min at a filament temperature of 280 oC. FTIR and XPS analyses of the deposited films confirmed that the epoxide functionality of the copolymers increased with increasing glycidyl methacrylate fraction in the reactor inlet. The potential of the glycidyl methacrylate containing copolymer films to act as substrates for protein immobilization was revealed. The immobilization of Human Serum Albumin (HSA), which is the main protein to carry fatty acids and metals to target tissues, was carried out via solid phase extraction. The effects of film composition and thickness on binding capacities of the protein to the polymers were studied. The maximum protein binding for the iCVD synthesized copolymer films was found to be 223 µg.cm-2 . Protein binding was also clarified by FTIR, AFM, and SEM analyses. The mild immobilization conditions, easy and rapid membrane preparation, one-step protein binding at substantially higher levels and membrane reusability make iCVD deposited P(HEMAGMA) films useful for biomolecules immobilization and for several biochemical processes.