Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing
For about 100 years, potentiometry with ion-selective electrodes has been one of the dominating electroanalytical techniques. While great advances in terms of selective chemistries and materials have been achieved in recent years, the basic manner in which ion-selective membranes are used has not fu...
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| Format: | Journal Article |
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Elsevier
2008
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| Online Access: | http://hdl.handle.net/20.500.11937/37459 |
| _version_ | 1848755053588905984 |
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| author | Bakker, Eric Bhakthavatsalam, V. Gemene, K. |
| author_facet | Bakker, Eric Bhakthavatsalam, V. Gemene, K. |
| author_sort | Bakker, Eric |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | For about 100 years, potentiometry with ion-selective electrodes has been one of the dominating electroanalytical techniques. While great advances in terms of selective chemistries and materials have been achieved in recent years, the basic manner in which ion-selective membranes are used has not fundamentally changed. The potential readings are directly co-dependent on the potential at the reference electrode, which requires maintenance and for which very few accepted alternatives have been proposed. Fouling or clogging of the exposed electrode surfaces will lead to changes in the observed potential. At the same time, the Nernst equation predicts quite small potential changes, on the order of millivolts for concentration changes on the order of a factor two, making frequent recalibration, accurate temperature control and electrode maintenance keyrequirements of routine analytical measurements. While the relatively advanced selective materials developed for ion-selective sensors would be highly attractive for low power remote sensing application, one should consider solutions beyond classical potentiometry to make this technology practically feasible. This paper evaluates some recent examples that may be attractive solutions to the stated problems that face potentiometric measurements. These include high-amplitude sensing approaches, with sensitivities that are an order of magnitude larger than predicted by the Nernst equation; backside calibration potentiometry, where knowledge of the magnitude of the potential is irrelevant and the system is evaluated from the backside of the membrane; controlled current coulometry with ion-selective membranes, an attractive technique for calibration-free reagent delivery without the need for standards or volumetry; localized electrochemical titrations at ion-selective membranes, making it possible to design sensors that directly monitor parameters such as total acidity for which volumetric techniques were traditionally used; and controlled potential coulometry, where all ions of interest are selectively transferred into the ion-selective organic phase, forming a calibration-free technique that would be exquisitely suitable for remote sensing applications. |
| first_indexed | 2025-11-14T08:50:11Z |
| format | Journal Article |
| id | curtin-20.500.11937-37459 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:50:11Z |
| publishDate | 2008 |
| publisher | Elsevier |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-374592019-02-19T05:35:06Z Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing Bakker, Eric Bhakthavatsalam, V. Gemene, K. Ion-selective electrodes Coulometry Remote sensing Calibration-free Reference electrode Chemical sensors For about 100 years, potentiometry with ion-selective electrodes has been one of the dominating electroanalytical techniques. While great advances in terms of selective chemistries and materials have been achieved in recent years, the basic manner in which ion-selective membranes are used has not fundamentally changed. The potential readings are directly co-dependent on the potential at the reference electrode, which requires maintenance and for which very few accepted alternatives have been proposed. Fouling or clogging of the exposed electrode surfaces will lead to changes in the observed potential. At the same time, the Nernst equation predicts quite small potential changes, on the order of millivolts for concentration changes on the order of a factor two, making frequent recalibration, accurate temperature control and electrode maintenance keyrequirements of routine analytical measurements. While the relatively advanced selective materials developed for ion-selective sensors would be highly attractive for low power remote sensing application, one should consider solutions beyond classical potentiometry to make this technology practically feasible. This paper evaluates some recent examples that may be attractive solutions to the stated problems that face potentiometric measurements. These include high-amplitude sensing approaches, with sensitivities that are an order of magnitude larger than predicted by the Nernst equation; backside calibration potentiometry, where knowledge of the magnitude of the potential is irrelevant and the system is evaluated from the backside of the membrane; controlled current coulometry with ion-selective membranes, an attractive technique for calibration-free reagent delivery without the need for standards or volumetry; localized electrochemical titrations at ion-selective membranes, making it possible to design sensors that directly monitor parameters such as total acidity for which volumetric techniques were traditionally used; and controlled potential coulometry, where all ions of interest are selectively transferred into the ion-selective organic phase, forming a calibration-free technique that would be exquisitely suitable for remote sensing applications. 2008 Journal Article http://hdl.handle.net/20.500.11937/37459 10.1016/j.talanta.2007.10.021 Elsevier fulltext |
| spellingShingle | Ion-selective electrodes Coulometry Remote sensing Calibration-free Reference electrode Chemical sensors Bakker, Eric Bhakthavatsalam, V. Gemene, K. Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing |
| title | Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing |
| title_full | Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing |
| title_fullStr | Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing |
| title_full_unstemmed | Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing |
| title_short | Beyond potentiometry: Robust electrochemical ion sensor concepts in view of remote chemical sensing |
| title_sort | beyond potentiometry: robust electrochemical ion sensor concepts in view of remote chemical sensing |
| topic | Ion-selective electrodes Coulometry Remote sensing Calibration-free Reference electrode Chemical sensors |
| url | http://hdl.handle.net/20.500.11937/37459 |