Electrochemical behavior of dopamine on La@C82-COOH/C60-COOH/C70-COOH modified electrodes

Three kinds of carboxyfullerenes, La@C82-COOH, C60-COOH and C70-COOH, were used to modify gold electrodes. The electrochemical behavior of dopamine (DA) at the carboxyfullerenes modified electrodes was studied using the cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. The C70-COOH modified electrodes performed the best among them. Under the optimal conditions, linear CV and DPV responses to DA concentration from 1 μmol/L to 13 μmol/L were observed, and the detection limit of DA was 1×10−2 μmol/L in the presence of 10 μmol/L uric acid (UA). The practical analytical utilities of the C70-COOH modified electrodes were demonstrated by the determination of DA HCl in the real samples of dopamine hydrochloride injection (DHI). Moreover, the modified electrodes exhibited good reproducibility and sensitivity, demonstrating its feasibility for analytical purpose.