title: Resolving Non-Specific and Specific Adhesive Interactions of Catechols at Solid/Liquid Interfaces at the Molecular Scale.
abstract: The adhesive system of mussels evolved into a powerful and adaptive system with affinity to a wide range of surfaces. It is widely known that thereby 3,4-dihydroxyphenylalanine (Dopa) plays a central role. However underlying binding energies remain unknown at the single molecular scale. Here, we use single-molecule force spectroscopy to estimate binding energies of single catechols with a large range of opposing chemical functionalities. Our data demonstrate significant interactions of Dopa with all functionalities, yet most interactions fall within the medium-strong range of 10-20 kB T. Only bidentate binding to TiO2 surfaces exhibits a higher binding energy of 29 kB T. Our data also demonstrate at the single-molecule level that oxidized Dopa and amines exhibit interaction energies in the range of covalent bonds, confirming the important role of Dopa for cross-linking in the bulk mussel adhesive. We anticipate that our approach and data will further advance the understanding of biologic and technologic adhesives.
authors.affiliation: Interface Chemistry and Surface Engineering, Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237, Düsseldorf, Germany. Utzig@mpie.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Utzig
authors.affiliation: Interface Chemistry and Surface Engineering, Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237, Düsseldorf, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Stock
authors.affiliation: Interface Chemistry and Surface Engineering, Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237, Düsseldorf, Germany. Valtiner@mpie.de.|Institut für physikalische Chemie, TU Bergakademie Freiberg, Leipziger Straße 29, 09599, Freiberg, Germany. Valtiner@mpie.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Valtiner
keywords: adhesion; biophysics; interfaces; nanotechnology; single-molecule force spectroscopy