Potentiometric Sensing

This review describes, with 186 references, progress in the field of potentiometric sensing in the period between January 2016 and August 2018. January 2016 was when the last fundamental review covering the topic of potentiometric sensors appeared in the special issue of Analytical Chemistry and was set as start date. This review starts with a description of progress in the development and improve-ment of reference electrodes, which represent an indispensable part of any electro-chemical cell and has a particularly important influence on the accuracy of potentiometric measurements. It continues with an overview of recent achievements and discoveries in the domain of solid-contact ion-selective electrodes. This section was structured mainly by the type of ion-to-electron transducing material dis-cussed. Next, insights into modern theory of potentiometry is given, describing the use of numerical simulation to predict time dependent potential changes at ion-selective membranes as well as new protocols for determining selectivity coefficient. Subsequently, new and non-classical readout principles for ion-selective electrodes are presented. It is followed by a section dedicated to new materials ex-ploited for ion-selective electrodes (ISEs), including membrane materials, ion-exchange nanopores, room temperature ionic liquids, molecular imprinted polymers and new ionophores. Recent developments in the area of miniaturized ISEs, including paper-based devices, wearable sensors, miniaturized pH sensors, ion-selective microelectrodes and ion-selective field effect transistors (ISFET), are discussed in the next section. The review ends with a discussion of some analytical applications for potentiometric sensors, including polyion detection and environmental, clinical and surfactant analysis.