title: Immobilization of methylene blue on self-assembled iodine monolayers on gold.
abstract: The immobilization of methylene blue (MB) on iodine-covered Au(111) is studied by electrochemical techniques, scanning tunneling microscopy (STM), Auger Electron Spectroscopy (AES), and Raman spectroscopy. Results show that MB species are efficiently adsorbed on the square root of 3 x square root of 3 R30 degrees I lattice on Au(111). The electrochemical behavior of the adsorbed MB molecules is reversible, indicating a relatively fast electron transfer from the Au(111) surface to the immobilized MB species through the iodine layer. STM images with molecular resolution are consistent with adsorption of MB dimers on a square root of 3 x square root of 3 R30 degrees I lattice placed atop of the Au(111) substrate. Results are compared to those obtained for MB immobilized on Au(111) covered by S(n) (n = 3-8) surface structures.
authors.affiliation: Instituto de Investigaciones Fisicoquímica Teóricas y Aplicadas, Universidad Nacional de La Plata - CONICET, Sucursal 4 Casilla de Correo 16 (1900) La Plata, Argentina.
authors.forename: María E
authors.initials: ME
authors.lastname: Vela
authors.forename: C
authors.initials: C
authors.lastname: Vericat
authors.forename: M A Daza
authors.initials: MA
authors.lastname: Millone
authors.forename: M
authors.initials: M
authors.lastname: Fonticelli
authors.forename: G
authors.initials: G
authors.lastname: Benitez
authors.forename: Roberto C
authors.initials: RC
authors.lastname: Salvarezza
authors.forename: Nicolás G
authors.initials: NG
authors.lastname: Tognalli
authors.forename: Alejandro
authors.initials: A
authors.lastname: Fainstein
mesh_terms: D000327:Adsorption; D019281:Dimerization; D004563:Electrochemistry / Q000379:methods*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006046:Gold / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry*; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling / Q000379:methods; D008956:Models, Chemical; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods*; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D004791:Enzyme Inhibitors; D006046:Gold; D007455:Iodine; D008751:Methylene Blue