Enhanced electrochemical response in oxidative differential pulse voltammetry of dopamine in the presence of ascorbic acid at carboxyl-terminated boron-doped diamond electrodes

Takeshi Kondo, Yu Niwano, Akira Tamura, Junichi Imai, Kensuke Honda, Yasuaki Einaga, Donald A. Tryk, Akira Fujishima, Takeshi Kawai

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The differential pulse voltammetric (DPV) peak for dopamine (DA) oxidation was found to be highly amplified by the addition of ascorbic acid (AA) when carboxyl-terminated boron-doped diamond (BDD) electrodes were used as the working electrode. The DP voltammogram for a solution containing DA and AA obtained using a 4-pentenoic acid-modified BDD (4PA-BDD) electrode showed well-separated oxidation peaks for DA and AA at 0.4 and 0.6 V vs. Ag/AgCl, respectively. In addition, as the DA concentration increased at constant AA concentration, a simultaneous increase in the DA peak current density and decrease in the AA peak current density were observed. The slope of the calibration curve for the [DA] range of 1-10 μM in the presence of AA (500 μM) was seven times larger than that obtained in the absence of AA. Such an enhancement was found to be more efficient at 4PA-BDD than at oxidized-BDD, partly due to simple electrostatic effects and partly due to suppression of the polymerization of DA oxidation products by the terminal carboxyl groups. The enhanced detection method using a carboxyl-terminated BDD electrode should be an effective analytical tool, especially for determining low concentrations of DA in the presence of high concentrations of AA.

Original languageEnglish
Pages (from-to)2312-2319
Number of pages8
JournalElectrochimica Acta
Volume54
Issue number8
DOIs
Publication statusPublished - 2009 Mar 1

Keywords

  • Boron-doped diamond
  • Carboxyl-terminated surface
  • Differential pulse voltammetry
  • Dopamine
  • Electrochemical amplification

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Electrochemistry

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