Determination of Dopamine at m-Aminophenol Modified Glassy Carbon Electrode

The glassy carbon electrode (GCE) was modified electrochemically on its surface with m-aminophenol (m-AP) in 0.1 mol·L-1 LiClO4 solution containing 2.0 mmol·L-1 m-AP at the potential of 0~1.5 V.This modified electrode described above was named abbreviately as m-AP/GCE.It was found that significant catalytic action of the m-AP/GCE was observed on the reaction of dopamine (DA) at the electrode.DA showed a pair of oxidation peak and reduction peak at m-AP/GCE,with potential difference of oxidation peak and reduction peak reduced to a value of 70mV as compared with its reaction at the bare GCE.Based on these findings,a selective method for determination of DA by cyclic voltammetry was proposed.Linear relationships between values of oxidation peak current and concentration of DA were obtained in the ranges of 1.2×10-7-9.1×10-6 and 9.1×10-6-1.2×10-4mol·L-1,with detection limit (3S/N) of 3.2×10-8mol·L-1.