Construction of Supramolecular Systems for the Selective and Quantitative Determination of Dopamine in the Presence of Ascorbic Acid

This work presents the construction of supramolecular systems formed by the modification of carbon paste electrodes, CPE, with multiwalled-carbon nanotubes, MWCNT, and b-cyclodextrin, CPE/MWCNT/β-CD, a novel conducting polymer produced by electrochemical polymerization of β-CD, CPE/poly-β-CD and another formed with MWCNT, β-CD and poly-β-CD, CPE/MWCNT/β-CD/poly-β-CD. With these modified electrodes, analyses were performed to understand the effect of such surface modifications on the electrochemical response of the analyte dopamine, which was surface-immobilized through formation of the said inclusion complex, as evidenced by the adsorption process that controlled the overall reaction rate of the oxidation process. Moreover, it is shown that the heterogeneous rate constant, k0, of Dopamine oxidation is highly increased in the presence of poly-β-CD.