Solid-contact potentiometric sensors based on silver nanoparticles in the supramolecular matrix for the determination of halogenide ions

Abstract

Determination of halogenide ions in pharmaceuticals and various waters is an actual task for the modern analytical chemistry. In the current work, solid-contact potentiometric sensor, based on the glassy carbon electrode covered with the layer of electropolymerized polyaniline and suspension of silver nanoparticles in the matrix of thiacalix[4]arene derivative bearing terminal catechol groups, has been described. The suspension was obtained by the chemical reduction of silver ions with the thiacalix[4]arene and drop casted on the polyaniline layer. The sensor showed potentiometric response to chloride-, bromide and iodide ions. For the simultaneous determination of iodide and bromide ions, a multi-sensor system, consisting of four electrodes with the different volumes of the suspension placed on the polyaniline layer, has been developed. The possibility of the response prediction within the simple additive model was found for the set of the iodide and bromide mixtures. In a similar manner, simultaneous determination of both ions in the variable mixtures has been performed. The multi-sensor system was tested during the determination of iodides in iodine containing pharmaceuticals and the determination of iodide and bromide ions in the artificial mineral water samples. Ionic chromatography was chosen as the comparison method. Sensors made it possible to determine from 0.1 μM to10 mMiodide and bromide ions in mixtures. The proposed approach and solid-contact potentiometric sensors can be used in the analysis of ion content of the waters and in control of the production and storage conditions of pharmaceuticals.