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 language | English |
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Pages (from-to) | 2312-2319 |
Number of pages | 8 |
Journal | Electrochimica Acta |
Volume | 54 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2009 Mar 1 |
Keywords
- Boron-doped diamond
- Carboxyl-terminated surface
- Differential pulse voltammetry
- Dopamine
- Electrochemical amplification
ASJC Scopus subject areas
- Chemical Engineering(all)
- Electrochemistry