The potentiometric response of electrodes is described, including: (1) Nernstian response to activity change due to an altered concentration of the analyte ion, and (2) Nernstian response to activity change caused by different solvents. In order to ensure the reliability of the data obtained in this study, the following three steps were taken: (i) a comparison of electrode potentials between a monovalent cation-sensitive glass electrode and amalgam electrodes; (ii) a comparison of the data with those obtained by other methods; and (iii) a comparison of the data obtained by employing different reference solvents. This review also describes the development of electrodes, including the synthesis of host compounds by esterification and amide bonding with poly(acrylamide), thermodynamic application results obtained by the developed electrodes, and brief discussions about the response mechanism and an establishment site of the membrane potential.