ION-SELECTIVE ELECTRODES BASED ON POLARIZABLE ELECTROLYTE/ELECTROLYTE SOLUTIONS INTERFACE

The interface between two immiscible electrolyte solutions can function as the electrode surface which responds selectively to specified ion(s), that is, as the ion-selective electrode(ISE). Both amperometry(or voltammetry) and potentiometry can be used. The amperometric ISE gives the current response which is proportional to the concentration of ion(s); whereas the potentiometric ISE gives the potential response which changes linearly with the logarithm of the activity of ion. Ion sensors based on the amperometric ISE are described.