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Intercalation Compounds as Inner Reference Electrodes for Reproducible and Robust Solid‐Contact Ion‐Selective Electrodes
Author(s) -
Ishige Yu,
Klink Stefan,
Schuhmann Wolfgang
Publication year - 2016
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201600111
Subject(s) - electrode , intercalation (chemistry) , robustness (evolution) , electrolyte , materials science , ion , reproducibility , lithium iron phosphate , chemistry , analytical chemistry (journal) , nanotechnology , electrochemistry , inorganic chemistry , chromatography , biochemistry , organic chemistry , gene
With billions of assays performed every year, ion‐selective electrodes (ISEs) provide a simple and fast technique for clinical analysis of blood electrolytes. The development of cheap, miniaturized solid‐contact (SC‐)ISEs for integrated systems, however, remains a difficult balancing act between size, robustness, and reproducibility, because the defined interface potentials between the ion‐selective membrane and the inner reference electrode (iRE) are often compromised. We demonstrate that target cation‐sensitive intercalation compounds, such as partially charged lithium iron phosphate (LFP), can be applied as iREs of the quasi‐first kind for ISEs. The symmetrical response of the interface potentials towards target cations ultimately results in ISEs with high robustness towards the inner filling (ca. 5 mV dec −1 conc.) as well as robust and miniaturized SC‐ISEs. They have a predictable and stable potential derived from the LiFePO 4 /FePO 4 redox couple (97.0±1.5 mV after 42 days).