A novel electrochemical synthesis of poly-3-methylthiophene-γ-cyclodextrin film -: Application for the analysis of chlorpromazine and some neurotransmitters

gamma-Cyclodextrin is an eight glucose unit conical structure, which possesses a hydrophobic internal cavity exhibiting supramolecular complexing properties and a hydrophilic exterior due to the presence of hydroxyl groups. In this work, we have synthesized for the first time a functionalized stable film of poly-3-methylthiophene combined with gamma-cyclodextrin (P3MT/-gamma-CD) in tetrabutylammonium hexafluorophosphate/acetonitrile solution. A potentiostatic mode was employed for the film growth. Cyclic voltammetry and electrochemical impedance spectroscopy were used for the characterization of the new film. The resulting conducting polymer sensor offers interesting analytical performances such as: (a) fast and linear responses towards the neurotransmitters dopamine and L-dopa towards the neuroleptic chlorpromazine with low detection limits of 2 x 10(-7), 10(-6), and 10(-7) M, respectively, and (b) simultaneous detection and well-resolved signals between the compounds of interest and ascorbic acid. To the best of our knowledge, these LOD are among the lowest found in the literature. Optimization of parameters such as interference effect, perm-selectivity, and mechanical stability of the sensor are discussed. (c) 2004 Elsevier B.V. All rights reserved.