Electrochemical properties of gold electrodes functionalized by new pseudo-polyrotaxanes of polyaniline and chemically modified β-cyclodextrin inclusion complex

This work explored the development of impedimetric sensors based on conducting polyaniline (PANI) and PANI-β-CDpNH2 thin films, formed by the complex inclusion of polyaniline with the modified β-cyclodextrin with amino groups. Thin films about 100 nm were deposited by thermal evaporation on gold electrodes. These thin films were characterized by the wettability technique for hydrophobicity analysis.The electrical properties of these polymer films have been studied by electrochemical impedance spectroscopy (EIS) technique. This study has revealed, according to an equivalent circuit fitting the experimental parameters, that PANI-β-CDpNH2 film is more conductive than PANI one. This result was explained by the PANI conformation changes from coiled and disorderly chain to rodlike one coated in the cavities of β-CD.Finally we have studied the electrochemical response of these electrodes towards Pb2+ cations in the aim to probe the contribution of PANI inclusion with β-CDpNH2 molecules to the enhancement of the sensitivity and recognition properties of these later. We have found that PANI-β-CDpNH2 film exhibits a good sensitivity towards the Pb2+ cations.

► PANI and PANI-β-CDpNH2 films are deposited on gold electrodes by evaporation process.
► The wettability results have shown a hydrophilic character of PANI-β-CDpNH2 film.
► EIS study has revealed that PANI-β-CDpNH2 film is more conductive than PANI one.
► PANI-β-CDpNH2 film exhibits a good sensitivity towards the Pb2+ cations.