This project aims to design and deploy robust potentiometric probes for the detection of a range of ionic species in aquatic samples. The work has an important fundamental components in which sensing principles are designed in view of the intended application. Cell symmetry helps to stabilize the signal. Activity coefficients are cancelled or compensated to achieve a concentration-based measurement (not activity). In situ calibration routines are developed to achieve very low power requirements. For marine applications a selective desalination cell was invented and deployed.

Publications:

(23)   Correction: A submersible probe with in-line calibration and a symmetrical reference element for continuous direct nitrate concentration measurements, Forrest, T.; Cherubini, T.; Jeanneret, S.; Zdrachek, E.; Damala, P.; Bakker, E. Environ. Sci.: Processes Impacts, 2023, 25, 1131 - 1132. DOI: 10.1039/d3em90017g (open access).

(22)   Submersible Probe with In-line Calibration and Symmetrical Reference Element for Continuous Direct Nitrate Measurements, Forrest, T.; Cherubini, T.; Jeanneret, S.; Zdrachek, E.; Damala, P.; Bakker, E. Environ. Sci.: Processes Impacts, 2023, 25, 519 - 530. DOI: 10.1039/D2EM00341D (open access).

(21) Zdrachek, E.; Forrest, T.; Bakker, E. Solid-Contact Potentiometric Cell with Symmetry. Anal Chem 2022, 94 (2), 612-617. DOI: 10.1021/acs.analchem.1c04722.

(20) Damala, P.; Zdrachek, E.; Forrest, T.; Bakker, E. Unconditioned Symmetric Solid-Contact Electrodes for Potentiometric Sensing. Anal Chem 2022. DOI: 10.1021/acs.analchem.2c01728.

(19) Damala, P.; Zdrachek, E.; Bakker, E. Commercially Available Nitrate Ionophores in Potentiometric Sensors Are Not Superior to Common Ion-exchangers. Electroanal 2022. DOI: 10.1002/elan.202200247.

(18) Zdrachek, E.; Bakker, E. Ion-to-electron capacitance of single-walled carbon nanotube layers before and after ion-selective membrane deposition. Microchim Acta 2021, 188 (5). DOI: 10.1007/s00604-021-04805-1.

(17) Soda, Y.; Bakker, E. Ionic strength-independent potentiometric cation concentration sensing on paper using a tetrabutylammonium-based reference electrode. Sensor Actuat B-Chem 2021, 346. DOI: 10.1016/j.snb.2021.130527.

(16) Zdrachek, E.; Bakker, E. Potentiometric Sensor Array with Multi-Nernstian Slope. Anal Chem 2020, 92 (4), 2926-2930. DOI: 10.1021/acs.analchem.9b05187.

(15) Kraikaew, P.; Jeanneret, S.; Soda, Y.; Cherubini, T.; Bakker, E. Ultrasensitive Seawater pH Measurement by Capacitive Readout of Potentiometric Sensors. ACS Sensors 2020, 5 (3), 650-654. DOI: 10.1021/acssensors.0c00031.

(14) Gao, W. Y.; Zdrachek, E.; Xie, X. J.; Bakker, E. A Solid-State Reference Electrode Based on a Self-Referencing Pulstrode. Angew Chem Int Edit 2020, 59 (6), 2294-2298. DOI: 10.1002/anie.201912651.

(13) Gao, W. Y.; Xie, X. J.; Bakker, E. Direct Potentiometric Sensing of Anion Concentration (Not Activity). ACS Sensors 2020, 5 (2), 313-318. DOI: 10.1021/acssensors.9b02523.

(12) Cuartero, M.; Crespo, G.; Cherubini, T.; Pankratova, N.; Confalonieri, F.; Massa, F.; Tercier-Waeber, M. L.; Abdou, M.; Schafer, J.; Bakker, E. In Situ Detection of Macronutrients and Chloride in Seawater by Submersible Electrochemical Sensors. Anal Chem 2018, 90 (7), 4702-4710. DOI: 10.1021/acs.analchem.7b05299.

(11) Athavale, R.; Pankratova, N.; Dinkel, C.; Bakker, E.; Wehrli, B.; Brand, A. Fast Potentiometric CO2 Sensor for High-Resolution in Situ Measurements in Fresh Water Systems. Environ Sci Technol 2018, 52 (19), 11259-11266. DOI: 10.1021/acs.est.8b02969.

(10) Pankratova, N.; Cuartero, M.; Cherubini, T.; Crespo, G. A.; Bakker, E. In-Line Acidification for Potentiometric Sensing of Nitrite in Natural Waters. Anal Chem 2017, 89 (1), 571-575. DOI: 10.1021/acs.analchem.6b03946.

(9) Cuartero, M.; Pankratova, N.; Cherubini, T.; Crespo, G. A.; Massa, F.; Confalonieri, F.; Bakker, E. In Situ Detection of Species Relevant to the Carbon Cycle in Seawater with Submersible Potentiometric Probes. Environ Sci Tech Let 2017, 4 (10), 410-415. DOI: 10.1021/acs.estlett.7b00388.

(8) Cuartero, M.; Bakker, E. Environmental water analysis with membrane electrodes. Curr Opin Electroche 2017, 3 (1), 97-105. DOI: 10.1016/j.coelec.2017.06.010.

(7) Athavale, R.; Dinkel, C.; Wehrli, B.; Bakker, E.; Crespo, G. A.; Brand, A. Robust Solid-Contact Ion Selective Electrodes for High-Resolution In Situ Measurements in Fresh Water Systems. Environ Sci Tech Let 2017, 4 (7), 286-291. DOI: 10.1021/acs.estlett.7b00130.

(6) Afshar, M. G.; Tercier-Waeber, M. L.; Wehrli, B.; Bakker, E. Direct sensing of total alkalinity profile in a stratified lake. Geochem Perspect Let 2017, 3 (1), 85-93. DOI: 10.7185/geochemlet.1709.

(5) Pankratova, N.; Afshar, M. G.; Yuan, D. J.; Crespo, G. A.; Bakker, E. Local Acidification of Membrane Surfaces for Potentiometric Sensing of Anions in Environmental Samples. ACS Sensors 2016, 1 (1), 48-54. DOI: 10.1021/acssensors.5b00015.

(4) Jansod, S.; Afshar, M. G.; Crespo, G. A.; Bakker, E. Alkalinization of Thin Layer Samples with a Selective Proton Sink Membrane Electrode for Detecting Carbonate by Carbonate-Selective Electrodes. Anal Chem 2016, 88 (7), 3444-3448. DOI: 10.1021/acs.analchem.6b00346.

(3) Bakker, E. Can Calibration-Free Sensors Be Realized? ACS Sensors 2016, 1 (7), 838-841. DOI: 10.1021/acssensors.6b00247.

(2) Yuan, D. J.; Anthis, A. H. C.; Afshar, M. G.; Pankratova, N.; Cuartero, M.; Crespo, G. A.; Bakker, E. All-Solid-State Potentiometric Sensors with a Multiwalled Carbon Nanotube Inner Transducing Layer for Anion Detection in Environmental Samples. Anal Chem 2015, 87 (17), 8640-8645. DOI: 10.1021/acs.analchem.5b01941.

(1) Pankratova, N.; Crespo, G. A.; Afshar, M. G.; Crespi, M. C.; Jeanneret, S.; Cherubini, T.; Tercier-Waeber, M. L.; Pomati, F.; Bakker, E. Potentiometric sensing array for monitoring aquatic systems. Environ Sci-Proc Imp 2015, 17 (5), 906-914. DOI: 10.1039/c5em00038f.

© Eric Bakker