Regensburg 2010 – scientific programme

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DS: Fachverband Dünne Schichten

DS 43: Biomolecular and Functional Organic Layers II (Focused Session)

DS 43.6: Talk

Friday, March 26, 2010, 13:00–13:15, H2

Avidin immobilization on mixed monomolecular template prepared by irradiation promoted exchange reaction — Nirmalya Ballav¹, Andreas Terfort², and •Michael Zharnikov¹ — ¹Angewandte Physikalische Chemie, Universität Heidelberg, 69120 Heidelberg, Germany — ²Institut für Anorganische und Analytische Chemie, Goethe-Universität Frankfurt, Germany

An applicability of irradiation-promoted exchange reaction (IPER) to the fabrication of mixed self-assembled monolayers (SAMs) comprised of the protein-repelling matrix and moieties bearing binding sites for specific attachment of a target protein is demonstrated. As test systems, we took mixed films of oligoethyleneglycol (OEG) substituted alkanethiols (OEG-ATs) and biotin-substituted alkanethiols (BATs) on Au(111). Such SAMs are suitable for specific immobilization of avidin and its variants. The SAM composition was precisely controlled by varying the irradiation dose, which is a prerequisite for the fabrication of the respective patterns by electron-beam lithography. While the general trend in the immobilization of avidin onto the mixed OEG-AT/BAT SAMs prepared by IPER was found to be consistent with the earlier reports regarding the analogous films fabricated by the co-assembly method, the concentration of the BAT component in the mixed SAMs needed for the maximum surface coverage of the specific protein was found to be lower and the maximum avidin coverage higher in the case of IPER than for the co-assembly method. We ascribe these differences to the lack of phase segregation and better separation of the BAT species in the OEG-AT matrix in the case of IPER.