A highly selective dopamine sensor was fabricated by doping polypyrrole with a sulfonated Î²-cyclodextrin. This composite material enabled the selective sensing of dopamine in the presence of a large excess of ascorbic acid and prevented the regeneration of dopamine through the homogeneous catalytic reaction of the ascorbate anion with the dopamine-o-quinone. A single redox wave, corresponding to the oxidation of dopamine, was observed in dopamine/ascorbate mixtures, giving a truly selective dopamine sensor. The limit of detection was measured as 3.2 Ã— 10-6 M for dopamine. Â© 2010 Elsevier B.V.