Immobilization of methylene blue on self-assembled iodine monolayers on gold.
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.
Vela
María E
ME
Instituto de Investigaciones Fisicoquímica Teóricas y Aplicadas, Universidad Nacional de La Plata - CONICET, Sucursal 4 Casilla de Correo 16 (1900) La Plata, Argentina.
Vericat
C
C
Millone
M A Daza
MA
Fonticelli
M
M
Benitez
G
G
Salvarezza
Roberto C
RC
Tognalli
Nicolás G
NG
Fainstein
Alejandro
A
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
D004791:Enzyme Inhibitors; D006046:Gold; D007455:Iodine; D008751:Methylene Blue