title: Surface chemistry of ultrathin films of histidine on gold as probed by high-resolution synchrotron photoemission.
abstract: Procedures for the vacuum deposition of thin histidine films on polycrystalline Au(111) and their characterization with high-resolution synchrotron-radiation-based photoelectron spectroscopy are reported. The chemical form of histidine (anionic vs zwitterionic) and the nature of its interactions with the substrate (strong ionic-covalent vs weak van der Waals bonding) in mono- and multilayer films are analyzed. It is shown that water adsorption on a pre-prepared histidine film at 100 K results in protonation of histidine molecules and partial formation of hydroxyl anions. These chemical effects are carefully differentiated from spectral changes associated with radiation damage of the histidine films.
authors.affiliation: Angewandte Physikalische Chemie, University of Heidelberg, INF 253, 69120 Heidelberg, Germany. yan.zubavichus@urz.uni-heidelberg.de
authors.forename: Yan
authors.initials: Y
authors.lastname: Zubavichus
authors.forename: Michael
authors.initials: M
authors.lastname: Zharnikov
authors.forename: Yongjie
authors.initials: Y
authors.lastname: Yang
authors.forename: Oliver
authors.initials: O
authors.lastname: Fuchs
authors.forename: Clemens
authors.initials: C
authors.lastname: Heske
authors.forename: Eberhard
authors.initials: E
authors.lastname: Umbach
authors.forename: George
authors.initials: G
authors.lastname: Tzvetkov
authors.forename: Falko P
authors.initials: FP
authors.lastname: Netzer
authors.forename: Michael
authors.initials: M
authors.lastname: Grunze
mesh_terms: D000327:Adsorption; D006046:Gold / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry* / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D015394:Molecular Structure; D017785:Photons; D012680:Sensitivity and Specificity; D013057:Spectrum Analysis / Q000379:methods; D013499:Surface Properties; D017356:Synchrotrons; D014867:Water / Q000737:chemistry; D014965:X-Rays
chemical_list: D008567:Membranes, Artificial; D014867:Water; D006639:Histidine; D006046:Gold