Electrochemically degraded dopamine film for the determination of dopamine

A dopamine (DA) polymer was deposited electrochemically on to a glassy carbon (GC) surface until the electrode surface was passivated. The DA film on the GC surface was re-formed for high sensitivity and reproducibility by electrochemical degradation. The re-formed electrode was sensitive and selective in the determination of DA in the presence of ascorbic acid. The linear range obtained by square-wave voltammetry was between 0.1 and 2.1 mu M (R= 0.996, n=6) with a sensitivity of 1.2 NA mu M-1 and a detection limit (S/N=3) of 0.04 mu M. The electropolymerized DA film was stable and the re-formed electrode was reproducible for DA determination.