“…It is well-known that the diffusion processes, controlling the rate of ion delivery from the bulk of the membrane and solution to the interface and vice versa, have a significant impact on the response of conventional ion-selective electrodes (ISEs), especially highly selective ones. − The consideration of the diffusion processes’ influence on the ISEs response, at a qualitative level, suggests various techniques for controlling the intensity of ion fluxes and direction by means of optimizing the design of ISEs, − membrane composition, − and inner filling solution − as well as using special algorithms of membrane conditioning (including impulse galvanostatic polarization − ) and measurements protocols. , As a result, the analytical characteristics of ISEs, including lower detection limit and selectivity, were drastically improved, and the application field of ISEs was significantly expanded. − Furthermore, it was shown that some electrodes provide an analytically significant response only under the condition of the diffusion control of the potential; in particular, the functioning of polyion sensors for determination of heparin and protamine is based on this discovery. − It was found that diffusion processes at the membrane–sample solution interface can lead to strong potential drift for highly selective electrodes in the solutions of foreign ions. − On the other hand, progress in computer science and in methods of numerical simulations have promoted the development of electrode potential models, ,− which are characterized by a different level of complexity and demonstrate a certain predictive ability. In some cases, these models can be used to quantitatively estimate the influence of the change in design of ISEs, measurements conditions, and protocols for the main analytical parameters and response characteristics of ISEs in a way which is faster and cheaper than by performing of the experiments.…”