Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with carbon nanotubes as ion-to-electron transducer in polymer membrane-based potassium ion-selective electrodes

Zekra Mousavi, Johan Bobacka, A Lewenstam, A Ivaska

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    Abstract

    Negatively charged multi-walled carbon nanotubes (MWCNTs) were used as dopants in the electrochemical synthesis of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). The resulting electroactive film, PEDOT(CNT), was used as ion-to-electron transducer (solid contact) in potassium ion-selective electrodes (K+-ISEs) based on plasticized PVC membrane containing valinomycin as neutral ionophore. Potentiometric measurements were carried out to study the analytical performance of solid-contact K+-ISEs, the influence of dissolved O-2 and CO2 on the potential of the electrodes, and the formation of the interfacial aqueous film. The prepared electrodes were also characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronopotentiometry. The experimental results showed that PEDOT(CNT) has the capability to function as solid contact in fabrication of K+-ISEs. These electrodes, based on PEDOT(CNT) as ion-to-electron transducer, showed high sensitivity and selectivity to K+ ion which can be related to the plasticized PVC-based ion-selective membrane containing valinomycin. The stability of the electrode potential, however, was found to depend on the conducting substrate used for deposition of the PEDOT(CNT) film. Results from the CV and EIS revealed that the PEDOT(CNT) contact exhibits high redox capacitance that is favorable for a solid contact. (C) 2009 Published by Elsevier B.V.
    Original languageUndefined/Unknown
    Pages (from-to)246–252
    Number of pages7
    JournalJournal of Electroanalytical Chemistry
    Volume633
    Issue number1
    DOIs
    Publication statusPublished - 2009
    MoE publication typeA1 Journal article-refereed

    Keywords

    • All-solid-state ion-selective electrode
    • Conducting polymers
    • Multi-walled carbon nanotubes
    • PEDOT
    • Potassium ion sensor

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