Carbon fiber microelectrodes electrocoated with polycarbazole and poly(carbazole-co-p-tolylsulfonyl pyrrole) films for the detection of dopamine in presence of ascorbic acid

Polycarbazole (PCz) and poly(carbazole-co-p-tolylsulfonyl pyrrole) (PCz-co-p-Tsp) films were electrochemically deposited on single carbon fiber microelectrodes using LiClO4 as electrolyte and acetonitrile as a solvent. The response of the sensors was tested towards different dopamine concentrations. The effect of ascorbic acid on the dopamine signal was analyzed by differential pulse voltammetry. Sensors displaying amperometric response to dopamine concentrations with a detection limit of 0.27 mu M dopamine (3S/N) for the PCz modified CFE and 0.5 mu M dopamine (3S/N) for the PCz-co-p-Tsp modified CFE; and an efficient protection against ascorbic acid interference at physiology concentration values (500 mu M) were obtained.