Bias current modifies the selectivity of liquid membrane ion-selective microelectrodes

Coles, J. A. (1988) Bias current modifies the selectivity of liquid membrane ion-selective microelectrodes. Pflügers Archiv - European Journal of Physiology, 411(3), pp. 339-344. (doi: 10.1007/BF00585125)

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A negative bias potential of up to −8- mV applied to the back of a liquid membrane ion-selective microelectrode containing classical “K+” ion-exchanger was found to make it more selective for millimolar concentrations of K+ over micromolar concentrations of choline, tetramethylammonium, tetraethylammonium and 5-hydroxytryptamine. Conversely, positive bias potential increased severalfold the sensitivity to micromolar concentrations of these ions while decreasing the sensitivity to K+. An increase in response amplitude for millimolar changes of ion concentration was also observed in neutral carrier electrodes for Na+, K+ and Ca2+ with negative bias potential. The various ions caused the resistances of the electrodes to change; these resistance changes contributed to the changes in response amplitude, but there were additional, unexplained, factors. The phenomenon was used to test if the signal from a K+ ion-exchanger microelectrode in extracellular space in bee retina was contaminated by substances other than K+.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Coles, Dr Jonathan
Authors: Coles, J. A.
College/School:College of Medical Veterinary and Life Sciences > Institute of Infection Immunity and Inflammation
Journal Name:Pflügers Archiv - European Journal of Physiology
Publisher:Springer Verlag
ISSN (Online):1432-2013

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