Abstrait

Electrochemical Behavior Of Dopamine In The Presence Of Ascorbic Acid On A Reduced Au/C60 Films Modified Glass Carbon Electrode

Ping Zhang, Guang-Chao Zhao

The Au/C60 nanoparticles was modified on the surface of glass carbon electrode by electroreducing the mixture of C60 and HAuCl4. SEM an AFM images displayed that the Au/C60 nanoparticles was tightly adsorbed on the surface of glass carbon electrode. After electrochemically reduced in 0.1M KOH, the surface of modified electrode was negatively charged which was proved by electrochemical characterization. The modified electrode was demonstrated to catalyze the electrochemical response of dopamine (DA) by cyclic voltammetry. The standard rate constant (Ks) for the electron transfer reaction of DA at the reduced Au/C60 films was found to be 1.38 × 10-2 cm/s. Furthermore, the separation between the voltammetric peaks of AA and DA is large, thus the simultaneous determination of AA and DA or the selective determination of DA in the presence of AA is feasible at the modified electrode. A linear response to DA and AA was obtained in the concentration range from 3.2 × 10-6 to 5.0 × 10-4 M and 8.0 × 10-6 to 5.0 × 10-3 M with a correlation coefficient of 0.9986 and 0.9997, respectively. The detection limit for dopamine was 2.0 × 10-7 and 5.3× 10-6 M for ascorbic acid. The proposed sensor has promising feature such as excellent sensitivity, good selectivity and high stability.