Novel ion-to-electron transduction principle for solid-contact ISEs

Solid-​contact ion-​selective electrodes (SC-​ISEs) are traditionally employed as potentiometric sensors, where the ion activity is related to the zero-​current potential of the sensor vs. the ref. electrode.  In this communication, an alternative ion-​to-​electron transduction principle for SC-​ISEs is introduced.  The suggested signal transduction principle resembles "const.-​potential coulometry" utilizing the redox capacitance of the internal solid contact in order to convert changes in ion concn. (activity) into elec. current and charge.  This short communication provides proof-​of-​concept for the suggested signal transduction method for SC-​ISEs utilizing poly(3,​4-​ethylenedioxythiphene) (PEDOT) as the solid contact that was coated with a cation-​sensitive polymeric membrane.