Description of ionophore-doped membranes with a blocked interface

Ion sensors with blocked interfaces, such as coated-wire electrodes (CWEs) and ion-selective field effect transistors (ISFETs), are increasingly being used as alternatives to traditional ion-selective electrodes (ISEs). This work provides insights into the behaviour of ionophore-doped membranes in solution, where one side completely blocks ion transfer, using the Nernst-Planck-Poisson (NPP) model, including reaction terms. Extensive investigations were conducted, demonstrating that the NPP model provides reasonable predictions, as well as insight into the interplay between interfacial kinetics, complexation, diffusion and electrical processes. Model validation is achieved through its application to and analysis of experimental results obtained for AlGaN/GaN ISFETs with ionophore-doped membranes.