Bottom up approaches for amino -CD adsorption on gold surfaces. A comparative study.

GUSTAVO A RIVAS, NANCY F FERREYRA*,; MARYCARMEN GARCIA; SOLEDAD BOLLO, CLAUDIA YAÑEZ.

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2016 vol. 203 p. 292 - 300

0013-4686

The immobilization of three amino-b-cyclodextrin derivatives on gold surfaces via different bottom-upapproaches was evaluated using cyclic voltammetry and surface plasmon resonance. Direct adsorptionon gold and covalent attachment via amide bond formation with carboxylic groups of both the selfassembled monolayer of 4-mercapto benzoic acid (4-MBA) and the electrografted diazonium saltsynthesized in situ from 4-amino benzoic acid (4-ABA) were tested. Amino b-CD with 1, 2 or 7 aminegroups on the primary rim were used. The influence of the immobilization methodologies on theelectrochemical properties of the resulting surfaces was studied using hydroquinone and ferricyanide asredox probes. The results indicate that the surface coverage of the molecules as well as their organizationat the gold substrate depends on the number of amine groups on the primary rim of b-CD. A highercoverage via direct adsorption is obtained using the 7-amino groups derivative, while the highestcoverage is reached with the 2-amino groups derivative via covalent attachment at diazonium saltelectrografted surfaces. A critical discussion about the influence of different strategies used for theimmobilization and the number of terminal amine groups on the b-CD structure is performed.