Armstrong W M, Garcia-Diaz J F
Fed Proc. 1980 Sep;39(11):2851-9.
This report reviews the use of ion-selective microelectrodes to measure intracellular ionic activities and ionic electrochemical potential differences across cell membranes. Particular emphasis is placed on the electrochemical characteristics of liquid ion-exchanger microelectrodes. Methods for assessing the effect of interfering ions on the electrode potential are discussed and analyzed. An equivalent electrical circuit model is proposed in which deviations from their theoretical values of the slopes and selectivities of liquid ion-exchanger microelectrodes are analyzed in terms of surface conductance phenomena. A quantitative expression is developed that permits the transmembrane electrochemical potential difference for an ion, which is measured with an ion-selective microelectrode, to be corrected for deviations from ideality in the slope of the electrode response. The effect of lipophilic anions, dissolved in the organic ion-exchanger solution, on the electrochemical characteristics of cation selective liquid ion-exchanger microelectrodes containing neutral ionophores is discussed.
本报告回顾了使用离子选择性微电极测量细胞内离子活性以及跨细胞膜的离子电化学势差的情况。特别强调了液体离子交换微电极的电化学特性。讨论并分析了评估干扰离子对电极电位影响的方法。提出了一个等效电路模型，根据表面电导现象分析了液体离子交换微电极斜率和选择性与其理论值的偏差。推导了一个定量表达式，该表达式可对用离子选择性微电极测量的离子跨膜电化学势差进行校正，以消除电极响应斜率偏离理想情况的影响。讨论了溶解在有机离子交换剂溶液中的亲脂性阴离子对含有中性离子载体的阳离子选择性液体离子交换微电极电化学特性的影响。
