Potentiometric sensors are the largest and most commonly used group of electrochemical sensors. Among them, ion-selective electrodes hold a prominent place. Since the end of the last century, their re-development has been observed, which is a consequence of the introduction of solid contact constructions, i.e., electrodes without an internal electrolyte solution. Research carried out in the field of potentiometric sensors primarily focuses on developing new variants of solid contact in order to obtain devices with better analytical parameters, and at the same time cheaper and easier to use, which has been made possible thanks to the achievements of material engineering. This paper presents an overview of new materials used as a solid contact in ion-selective electrodes over the past several years. These are primarily composite and hybrid materials that are a combination of carbon nanomaterials and polymers, as well as those obtained from carbon and polymer nanomaterials in combination with others, such as metal nanoparticles, metal oxides, ionic liquids and many others. Composite materials often have better mechanical, thermal, electrical, optical and chemical properties than the original components. With regard to their use in the construction of ion-selective electrodes, it is particularly important to increase the capacitance and surface area of the material, which makes them more effective in the process of charge transfer between the polymer membrane and the substrate material. This allows to obtain sensors with better analytical and operational parameters. Brief characteristics of electrodes with solid contact, their advantages and disadvantages, as well as research methods used to assess their parameters and analytical usefulness were presented. The work was divided into chapters according to the type of composite material, while the data in the table were arranged according to the type of ion. Selected basic analytical parameters of the obtained electrodes have been collected and summarized in order to better illustrate and compare the achievements that have been described till now in this field of analytical chemistry, which is potentiometry. This comprehensive review is a compendium of knowledge in the research area of functional composite materials and state-of-the-art SC-ISE construction technologies.

Use of the nanocomposite of chloride-doped polyaniline nanofibers and multiwalled carbon nanotubes (PANINFs-Cl:MWCNTs) for construction of ion-selective electrodes with solid-contact sensitive to chloride ions has been described. Many types of electrodes were tested, differing in the quantitative and qualitative composition of the layer placed between the electrode material and the ion-selective membrane. Initial tests were carried out, including tests of electrical properties of intermediate solid-contact layers. The obtained ion-selective electrodes had a theoretical slope of the electrode characteristic curve (−61.3 mV dec⁻¹), a wide range of linearity (5 × 10⁻⁶–1 × 10⁻¹ mol L⁻¹) and good potential stability resistant to changing measurement conditions (redox potential, light, oxygen). The chloride contents in the tap, mineral and river water samples were successfully determined using the electrodes.

Ginger (Zingiber officinale Rosc.) is a plant known all over the world that is used as a spice and as an ingredient in drinks, dietary supplements, and cosmetics. The growing availability of its fresh rhizomes makes it even more likely to be used in the diet, mainly due to its beneficial health properties and high content of polyphenols (gingerols and shogaols). The main goal and motivation of the authors was to assess the bioavailability of active substances contained in the extract from ginger rhizomes in the presence of various types of diets using the in vitro digestion method, enabling simulation of the processes occurring during the digestion and absorption of metabolites in the small intestine. For the qualitative and quantitative analyses, the HPLC-MS (High Performance Liquid Chromatography–Mass Spectrometry) and HPLC (High Performance Liquid Chromatography) techniques were used, respectively. Based on the obtained results, it was found that the best bioavailability of the selected ginger polyphenols (6-gingerol, 8-gingerdione, 8-shogaol, and 10-gingerdione) was estimated for a high-fiber diet, while the weakest results were obtained for standard and basic diets. In the case of the high-fiber diet, the bioavailability of the mentioned compounds was estimated as 33.3, 21.4, 6.73, and 21.0%, while for the basic diet, it was only 21.3, 5.3, 2.0, and 1.0%, respectively.

Ion-selective electrodes are a popular analytical tool useful in the analysis of cations and anions in environmental, industrial and clinical samples. This paper presents an overview of new materials used for the preparation of anion-sensitive ion-selective electrodes during the last five years. Design variants of anion-sensitive electrodes, their advantages and disadvantages as well as research methods used to assess their parameters and analytical usefulness are presented. The work is divided into chapters according to the type of ion to which the electrode is selective. Characteristics of new ionophores used as the electroactive component of ion-sensitive membranes and other materials used to achieve improvement of sensor performance (e.g., nanomaterials, composite and hybrid materials) are presented. Analytical parameters of the electrodes presented in the paper are collected in tables, which allows for easy comparison of different variants of electrodes sensitive to the same ion.