Selective Electrochemical Detection of Dopamine in the Presence of Ascorbic Acid at Anodized Diamond Thin Film Electrodes

摘要

Selective, highly stable determination of dopamine(DA) was achieved in cyclic voltammetric andchronoamperometric measurements carried out atelectrochemically treated conductive diamond film electrodes.The treated electrodes exhibited substantial shifts in the positivedirection for the peak potential for ascorbic acid (AA) oxidation,thus making it possible to discriminate between the DA and AAresponses. Linear calibration curves were obtained for both ahigher concentration range (1-70 μM DA, 1 mM AA ) and alower range (0.1-1 μM DA, 0.1 mM AA ) using voltammetryand chronoamperometry, respectively. The detection limit appearsto be on the order of 50 nM, which is among the lowest valuesreported thus far. Selectivity was also achieved in pH 7.0aqueous solution using more stringent electrochemicalytreatment, but the effect was relatively short-lived (up to 2h).