Electrochemical study of self-assembled monolayers of a β-cyclodextrin methyl sulfide covalently linked to anthraquinone

Keith J. Stine, Donna M. Andrauskas, Abdul R. Khan, P. Forgó, Valerian T. D'Souza

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Self-assembled monolayers of a β-cyclodextrin with methyl sulfides on the primary sites of the molecule and mono-functionalized with anthraquinone on a secondary site have been formed on gold electrodes. The surface coverages obtained by electrochemistry are consistent with values reported previously or calculated for similar non-electroactive β-CD derivatives. The electron transfer rate constants vary markedly with pH, increasing rapidly between pH 7 and 9 to values of approximately 700-900 s-1. These values are faster than reported previously for thiol derivatives of anthraquinone dispersed in an alkylthiol SAM matrix. Near pH 6, slow electron transfer is observed with a splitting into individual one-electron steps. Lowering the pH further results in very sluggish kinetics and indistinguishable peaks. Inclusion of naphthalene into the β-CD cavity appears to affect the anodic rate constant, and a small potential shift occurs. The efficient electron transfer of the anthraquinone spaced from the gold surface by a β-CD unit suggests promise for use of such molecules as `immobilized artificial enzymes'.

Original languageEnglish
Pages (from-to)209-218
Number of pages10
JournalJournal of Electroanalytical Chemistry
Volume465
Issue number2
DOIs
Publication statusPublished - Apr 29 1999

Fingerprint

Anthraquinones
Cyclodextrins
Self assembled monolayers
Sulfides
Electrons
Gold
Rate constants
Derivatives
Molecules
Electrochemistry
Naphthalene
Sulfhydryl Compounds
Enzymes
Electrodes
Kinetics

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Analytical Chemistry
  • Electrochemistry

Cite this

Electrochemical study of self-assembled monolayers of a β-cyclodextrin methyl sulfide covalently linked to anthraquinone. / Stine, Keith J.; Andrauskas, Donna M.; Khan, Abdul R.; Forgó, P.; D'Souza, Valerian T.

In: Journal of Electroanalytical Chemistry, Vol. 465, No. 2, 29.04.1999, p. 209-218.

Research output: Contribution to journalArticle

Stine, Keith J. ; Andrauskas, Donna M. ; Khan, Abdul R. ; Forgó, P. ; D'Souza, Valerian T. / Electrochemical study of self-assembled monolayers of a β-cyclodextrin methyl sulfide covalently linked to anthraquinone. In: Journal of Electroanalytical Chemistry. 1999 ; Vol. 465, No. 2. pp. 209-218.
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