Cyclic Voltammetry and Impedance Spectroscopy Behavior Studies of Polyterthiophene Modified Electrode

We present in this work a study of the electrochemical behaviour of terthiophene and its corresponding polymer, which is obtained electrochemically as a film by cyclic voltammetry (CV) on platinum electrode. The analysis focuses essentially on the effect of two solvents acetonitrile and dichloromethane on the electrochemical behaviour of the obtained polymer. The electrochemical behavior of this material was investigated by cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The voltammograms show that the film of polyterthiophene can oxide and reduce in two solutions; in acetonitrile, the oxidation current intensity is more important than in dichloromethane. The impedance plots show the semicircle which is characteristic of charge-transfer resistance at the electrode/polymer interface at high frequency and the diffusion process at low frequency

A surface acoustic wave sensor functionalized with a polypyrrole molecularly imprinted polymer for selective dopamine detection

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High Performance Zinc Oxide Nanorod-Doped Ion Imprinted Polypyrrole for the Selective Electrosensing of Mercury II Ions

A biomimetic, ion-imprinted polymer (IIP) was prepared by electropolymerization of pyrrole at the surface of gold electrodes decorated with vertically grown ZnO nanorods. The vertical growth of the nanorods was achieved via an ultrathin aryl monolayer grafted by reduction of diazonium salt precursor. Pyrrole was polymerized in the presence of L-cysteine as chelatant agent and Hg(II) (template). Hg(II)-imprinted polypyrrole (PPy) was also prepared on bare gold electrode in order to compare the two methods of sensor design (Au-ZnO-IIP vs Au-IIP). Non-imprinted PPy was prepared in the same conditions, however in the absence of any Hg2+ template. The strategy combining diazonium salt modification and ZnO nanorod decoration of gold electrodes permitted to increase considerably the specific surface and thus to improve the sensor performances. The limit of detection (LOD) of the designed sensor was ~1 pM, the lowest value ever reported in literature. The dissociation constants between PPy and Hg2+ were estimated at [Kd1 = (7.89 ± 3.63) mM and Kd2 = (38.10 ± 9.22) pM]. The sensitivity of the designed sensor was found to be 0.692 ± 0.034 μA/pM. The Au-ZnO-IIP was found to be highly selective towards Hg(II) compared to cadmium, lead and copper ions. This sensor design strategy could open up new horizons in monitoring toxic heavy metal ions in water and therefore contribute to enhance environmental quality

High Performance Zinc Oxide Nanorod-Doped Ion Imprinted Polypyrrole for the Selective Electrosensing of Mercury II Ions

International audienceA biomimetic, ion-imprinted polymer (IIP) was prepared by electropolymerization of pyrrole at the surface of gold electrodes decorated with vertically grown ZnO nanorods. The vertical growth of the nanorods was achieved via an ultrathin aryl monolayer grafted by reduction of diazonium salt precursor. Pyrrole was polymerized in the presence of L-cysteine as chelating agent and Hg 2+ (template). Hg 2+-imprinted polypyrrole (PPy) was also prepared on a bare gold electrode in order to compare the two methods of sensor design (Au-ZnO-IIP vs. Au-IIP). Non-imprinted PPy was prepared in the same conditions but in the absence of any Hg 2+ template. The strategy combining diazonium salt modification and ZnO nanorod decoration of gold electrodes permitted us to increase considerably the specific surface area and thus improve the sensor performance. The limit of detection (LOD) of the designed sensor was~1 pM, the lowest value ever reported in the literature for gold electrode sensors. The dissociation constants between PPy and Hg 2+ were estimated at [K d1 = (7.89 ± 3.63) mM and K d2 = (38.10 ± 9.22) pM]. The sensitivity of the designed sensor was found to be 0.692 ± 0.034 µA.pM −1. The Au-ZnO-IIP was found to be highly selective towards Hg 2+ compared to cadmium, lead and copper ions. This sensor design strategy could open up new horizons in monitoring toxic heavy metal ions in water and therefore contribute to enhancing environmental quality

Zinc Oxide Nanorods Wrapped with Ion-Imprinted Polypyrrole Polymer for Picomolar Selective and Electrochemical Detection of Mercury II Ions

This study concerns the design of an ion-imprinted polymer (IIP) for the selective detection of mercury II ions. Compared to other electrochemical studies, the originality of this work lies to the fact that the IIP was electropolymerized on ZnO nanorods, which were themselves grown on gold/diazonium modified substrates. This strategy of diazonium salt and ZnO nanorods permits to increase considerably the specific surface and thus to improve the sensor’s performances. The limit of detection (LOD) of the designed sensor was of order of 1 pM, the lowest value ever reported in literature

Design of L-Cysteine and Acrylic Acid Imprinted Polypyrrole Sensors for Picomolar Detection of Lead Ions in Simple and Real Media

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