The Selective Electrochemical Detection of Dopamine Using a Sulfated β-Cyclodextrin Carbon Paste Electrode

The present work describes a novel approach for the determination of dopamine (DA) using carbon paste electrodes modified with sulfated beta-cyclodextrin (S-beta-CDCPE). The electrodes show high affinity towards DA electrochemical oxidation. DA returned a concentration detection range 5 x 10(-7) M to 5 x 10(-4) M and a detection limit of 1.33 x 10(-7) M. DA, ascorbic acid (AA), and serotonin (5-HT) in a solution mixture can be simultaneously oxidized at significantly different potentials in the presence of S-beta-CDCPE, while the unmodified CPE returned an overlapping response. In particular, S-beta-CD-modified carbon paste microelectrode exhibits clear peak potential separations of 0.161, 0.101, and 0.258 V (vs. Ag/AgCl) for AA/DA, DA/5-HT, and AA/5-HT, respectively, in artificial cerebrospinal fluid (aCSF).