In recent years, an important aspect of research into the improvement of ion-selective electrodes (ISEs) has been the development of solid-contact ISEs for calibration-free measurements, with the goal of sensors that can be implemented with ease for long-term, in situ analysis with very limited or no maintenance. This review discusses the definition of the term “calibration-free” in this context, and it gives suggestions as to what types of information should be reported if a claim of calibration-free usage is made. Relevant literature in this field is reviewed, with a focus on different mechanisms of ion-to-electron signal transduction. Different types of redox-active, capacitive, and mixed-mechanism transduction modes are discussed in view of the reproducibility and stability of the potential responses they provide.
Bibliographical noteFunding Information:
This work was supported by the National Science Foundation ( CHE-1710024 ) to P.B. as well as a Kenneth E. & Marion S. Owens Endowed Fellowship from the University of Minnesota , a ThinkSwiss fellowship from the Swiss State Secretariat for Education, Research and Innovation, and a Graduate Research Fellowship from the National Science Foundation to C.R.R.
© 2021 Elsevier B.V.
- Ion-selective electrodes
- Solid contact