Peer-Reviewed Journal Details
Mandatory Fields
Boland, S,Foster, K,Leech, D
2009
February
Electrochimica Acta
A stability comparison of redox-active layers produced by chemical coupling of an osmium redox complex to pre-functionalized gold and carbon electrodes
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Osmium Redox active immobilized layer Diazonium salt Self-assembled monolayer SELF-ASSEMBLED MONOLAYERS ATOMIC-FORCE MICROSCOPY GLASSY-CARBON ELECTROCHEMICAL REDUCTION DIAZONIUM SALTS COVALENT MODIFICATION ARYLDIAZONIUM SALTS BIOFUEL CELL MULTILAYER FORMATION MODIFIED POLYPYRROLE
54
1986
1991
The production of stable redox active layers on electrode surfaces is a key factor for the development of practical electronic and electrochemical devices. Here, we report on a comparison of the stability of redox layers formed by covalently coupling an osmium redox complex to pre-functionalized gold and graphite electrode surfaces. Pre-treatment of gold and graphite electrodes to provide surface carboxylic acid groups is achieved via classical thiolate self-assembled monolayer formation on gold surfaces and the electro-reduction of an in situ generated aryldiazonium salt from 4-aminobenzoic acid on gold, glassy carbon and graphite surfaces. These surfaces have been characterized by AFM and electrochemical blocking studies. The surface carboxylate is then used to tether an osmium complex, [Os( 2,2'-bipyridyl)(2)(4-aminomethylpyridine)Cl]PF6, to provide a covalently bound redox active layer, E-0' of 0.29V (vs. Ag/AgCl in phosphate buffer, pH 7.4), on the pre-treated electrodes. The aryldiazonium salt-treated carbon-based surfaces showed the greatest stability, represented by a decrease of <5% in the peak current for the Os(II/III) redox transition of the immobilized complex over a 3-day period, compared to a decrease of 19% and 14% for the aryldiazonium salt treated and thiolate treated gold surfaces, respectively, over the same period. (C) 2008 Elsevier Ltd. All rights reserved.
DOI 10.1016/j.electacta.2008.09.066
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