ISSN:
0006-3592
Schlagwort(e):
Chemistry
;
Biochemistry and Biotechnology
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Biologie
,
Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
Notizen:
Enzyme-potentiometric sensors in which the chemical conversion of the analyte leads to the formation of an acid and/or a base can often display complex response characteristics. In these sensors, the, electrochemically monitored species is usually the H+ ion (pH-based sensors). However, in some cases the conjugate-ion of the H+ (or OH-) ion of the acid (or base) produced-can also be monitored - a specific example being the urease-NH4+ sensor. The response of both types of sensors is strongly affected by: (1) the degree of dissociation of the products and their transport properties in the enzymic film, (2) the amounts of pH-buffers present in the test solution, (3) the test solution's pH, and (4) the diffusion coefficients of the various species. In this article, a previously developed theoretical model for pH-based sensors - in which the differences in diffusivities of the various species were ignored - is generalized to accommodate for such differences, and extended to the latter of the above two types of sensors. It is shown that when the sensor operates under analyte diffusion-controlled conditions, the response of either type of sensor can be predicted by a simple algebraic equation which is independent of the actual kinetics of the enzymic reaction.
Zusätzliches Material:
9 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/bit.260370209
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