Cyclodextrin - ferrocene host - guest complexes on silicon oxide surfaces

Research on carbohydrate‐based interactions with proteins, nucleic acids, or antibodies has gained increased interest in the last years especially in clinical diagnosis or drug development. The efficiency of diagnostic interfaces depends upon the number of probe molecules, e.g., carbohydrates. The control of surface parameters as density and distribution of immobilized carbohydrates is essential for a reliable interaction with protein analytes. A controlled production of biomolecular interfaces can be reached by a stepwise quality control during buildup of these biointerfaces. Here, ß‐amino‐cyclodextrin molecules were attached to amine‐reactive silicon oxide surfaces via click chemistry to construct a model biosensor surface. The amount of surface bound carbohydrates was determined indirectly after chemical derivatization with 4‐(trifluoromethyl)‐benzylamine (TFMBA). Moreover, these surfaces were used to form host–guest complexes of ferrocene (guest) and β‐cyclodextrin (host) moieties to mimic the target binding (sensing) of the model biosensor. Surface chemical analysis of all steps during biosensor construction was performed using X‐ray photoelectron spectroscopy and near‐edge X‐ray absorption fine structure spectroscopy. Our approach widens the possibilities to generate switchable surfaces based on ß‐cyclodextrin surfaces for biosensor applications. Copyright © 2016 John Wiley & Sons, Ltd.