Potentiometric Fluoride Detection—Recent Achievements and Challenges

Potentiometric sensors constitute one of the most important groups of electrochemical sensors. Among them, ion-selective electrodes hold a prominent place. Potentiometry with fluoride ion-selective electrodes remains among the most common analytical methods for fluoride determination due to its high selectivity, cost-effectiveness, capability for in situ analysis, and wide-ranging environmental and biomedical applications. This paper provides a critical review of the development of fluoride ion-selective electrodes over the past decade, with particular emphasis on their design and analytical properties. It discusses the most important design approaches, highlighting their advantages, limitations, and challenges associated with miniaturisation or even leaching of the membrane. The properties of active membrane components responsible for fluoride-ion detection are discussed, along with the key analytical performance parameters that determine the selectivity, sensitivity, and reliability of fluoride determination. In the final section, the main areas of application for fluoride electrodes are characterised, with particular emphasis on their role in the analysis of environmental samples and biological materials.