title: Atomic force microscope imaging contrast based on molecular recognition.
abstract: The contrast in atomic force microscope images arises from forces between the tip and the sample. It was shown recently that specific molecular interaction forces may be measured with the atomic force microscope; consequently, we use such forces to map the distribution of binding partners on samples. Here we demonstrate this concept by imaging a streptavidin pattern with a biotinylated tip in a novel imaging mode called affinity imaging. In this mode topography, adhesion, and sample elasticity are extracted online from local force scans. We show that this technique allows the separation of these values and that the measured binding pattern is based on specific molecular interactions.
authors.affiliation: Lehrstuhl für Angewandte Physik, Ludwig Maximilians Universität, München, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Ludwig
authors.forename: W
authors.initials: W
authors.lastname: Dettmann
authors.forename: H E
authors.initials: HE
authors.lastname: Gaub
mesh_terms: D000268:Adhesiveness; D001360:Avidin; D001426:Bacterial Proteins / Q000737:chemistry*; D001710:Biotin; D002240:Carbohydrate Sequence; D003911:Dextrans / Q000737:chemistry; D006046:Gold; D006860:Hydrogen Bonding; D018625:Microscopy, Atomic Force / Q000379:methods*; D008969:Molecular Sequence Data; D011487:Protein Conformation; D019809:Streptavidin
chemical_list: D001426:Bacterial Proteins; D003911:Dextrans; D001360:Avidin; D001710:Biotin; D006046:Gold; D019809:Streptavidin