Electrocatalytic property of poly-chromotrope 2B modified glassy carbon electrode on dopamine and its application

A sensitive and selective electrochemical method for the determination of dopamine (DA) was developed by using poly-chromotrope 2B (PCR2B) modified glassy carbon electrode (GCE). This kind of modified electrode shows excellently electrocatalytic activity towards the oxidation of DA. The linear range of 2.0 × 10−6 to 8.0 × 10−5 M and a detection limit of 3.0 × 10−7 M were observed in pH 5.0 phosphate buffer solutions (PBS). The modified GCE exhibits potent and persistent electron-mediating behavior followed by well-separated oxidation peaks in cyclic voltammetry (CV) or differential pulse voltammetry (DPV) towards DA, Ascorbic acid (AA) and Uric acid (UA) with activation overpotentials. The ternary mixture which contains AA, DA and UA can be well separated from each other at a scan rate of 100 mV with a potential difference of 179, 165 and 344 mV in CV, and 200, 152 and 352 mV in DPV between AA and DA, DA and UA, and AA and UA, respectively. The differences are large enough to determine AA, DA and UA individually and simultaneously. This approach is so simple and easy that it can be used to selectively detect DA in the presence of AA and UA.