Voltammetric Determination of Dopamine and Uric Acid with Poly 2,6-diamino-4,5,6,7-tetrahydrobenzothiazole Modified Glassy Carbon Electrode

Polished and cleaned GCE was placed into 1 mmol·L-1 2,6-diamino-4,5,6,7-tetrahydrobenzothiazole (DATHBT) solution, and treated by CV for 15 cycles at a rate of 0.05 V·s-1 in the potential range of -0.6 V to 2.0 V to prepare poly DATHBT membrane modified GCE (PDATHBT/GCE). It was found that catalytic oxidation of dopamine (DA) and uric acid (UA) was observed at this modified electrode, and 2 clearly separated and sensitive oxidation peaks of DA and UA were found, while in contrast to the bare GCE, over-lapped peaks of DA and UA were obtained. Linear relationships between values of the oxidation peak current and concentration of DA and UA were found in the ranges of 0.1-100 μmol·L-1 and 2-1 000 μmol·L-1 respectively with detection limits (3S/N) of 0.05 μmol·L-1 for DA and 0.2 μmol·L-1 for UA. Values of recovery found by standard addition method were in the ranges of 97.0%-100% for DA and 96.5%-110% for UA with RSD′s (n=6) all less than 3.5%.