Electrochemical Elegance: A Comprehensive Review Of Advancements In Miniaturized Solid-State Ion-Selective Electrodes For Ion Sensing
Wei Chen
Chongqing Special Equipment Inspection and Research Institute, Chongqing, 401121, China
Xiaojie Wang
Key Laboratory of Electromechanical Equipment Security in Western Complex Environment for State Market Regulation, Chongqing, 401121, China
Abstract
The electrochemical method, a technique reliant on the distinctions in properties among diverse substances, hinges on the detection of electrical signals within the testing detection system [1]. In contrast to conventional methods such as titration, spectroscopy, and chromatography that analyze the total concentration of ions, the ion-selective electrode (ISE) operates on a distinct principle. It converts the ion activity to be measured into an electromotive force. Functioning as potent potentiometric chemical sensors, ion-selective electrodes (ISEs) offer a range of merits, including compact dimensions, rapid response times, user-friendliness, and cost-effectiveness. They have found extensive application in environmental monitoring, industrial analysis, and clinical testing [2]. Notably, the ion-selective electrode method's detection limit remains unaffected by the sample quantity, rendering it particularly suitable for microanalysis. The innovation of the all-solid-state ion-selective electrode is a noteworthy evolution in this domain. It substitutes the conventional filling liquid in liquid-junction ion-selective electrodes with a solid-state conversion layer. This ingenious substitution circumvents the shortcomings associated with traditional liquid-junction ion-selective electrodes, such as filling liquid leakage and limited miniaturization capabilities. Contrasting with its liquid-junction counterparts that often possess a relatively large volume, the all-solid-state ion-selective electrode showcases inherent ease of integration and miniaturization. Researchers have recognized the potential of a new all-solid-state ion-selective electrode devoid of inner liquid, paving the way for innovative developments in this field.