Effect of surface coverage of gold(111) electrode with cysteine on the chiral discrimination of DOPA

Mariko Matsunaga, Takuya Nakanishi, Toru Asahi, Tetsuya Osaka

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18 Citations (Scopus)


The enantioselectivity imparted to a gold electrode by modifying its surface with a self-assembled monolayer (SAM) of cysteine (Cys) was investigated for the electrochemical redox reaction of 3,4-dihydroxyphenylalanine (DOPA). A cyclic voltammetric study of the redox reaction revealed that the enantioselectivity was determined by the surface coverage of the gold electrode with Cys molecules. The electrode modified with ∼1.8 × 1014 Cys molecules cm-2 exhibited enantioselectivity in the voltammogram for the oxidation and reduction of DOPA, while the voltammograms obtained by the electrodes with either more or less surface coverages did not exhibit significant enantioselectivity. It is suggested that the accessibility of DOPA to that area of the gold surface which is not blocked by Cys molecules at an optimum surface coverage, is required for the enantioselective redox reaction of DOPA to proceed.

Original languageEnglish
Pages (from-to)295-299
Number of pages5
Issue number4
Publication statusPublished - 2007 May 2



  • Amino acids
  • Chiral discrimination
  • Chiral sensing
  • Cyclic voltammetry
  • Electrochemical method
  • Self-assembled monolayers

ASJC Scopus subject areas

  • Analytical Chemistry
  • Catalysis
  • Pharmacology
  • Drug Discovery
  • Spectroscopy
  • Organic Chemistry

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