Modelling of non-steady-state concentration profiles at ISFET-based coulometric sensor—actuator systems
Olthuis, W. and Luo, J. and Schoot, B.H. van der and Bergveld, P. and Bos, M. and Linden, W.E. van der (1990) Modelling of non-steady-state concentration profiles at ISFET-based coulometric sensor—actuator systems. Analytica Chimica Acta, 229 . pp. 71-81. ISSN 0003-2670
|Abstract:||Acid or base concentrations can be determined very rapidly by performing an acid—base titration with coulometrically generated OH− or H+ ions at a noble metal actuator electrode in close proximity to the pH-sensitive gate of an ion-sensitive field effect transistor (ISFET). The ISFET is used as the indicator electrode to detect the equivalence point in the titration curve. Typical values for the time needed to reach the equivalence point are 0.5–10 s for acid or base concentrations ranging from 0.5 × 10−3 to 20 × 10−3 mol l−1.
A model is presented, giving an analytical description of the diffusion phenomena that occur with the sensor—actuator system. The results of this analytical model description, using linearized concentration gradients, are presented together with the results of numerical simulations. Both results are in good agreement with measurements.
|Copyright:||© 1990 Elsevier|
Electrical Engineering, Mathematics and Computer Science (EEMCS)
|Link to this item:||http://purl.utwente.nl/publications/72901|
|Export this item as:||BibTeX|
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