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Typical ion-selective electrodes (ISEs) used in potentiometric mode suffer from low sensitivity, determined by Nernst (Nikolsky-Eisenman) equation. This limits resolution of potentiometric analysis, ultimately leading to significant problems in determination of relatively small changes of analyte ions concentration. A novel method was proposed using a ‘reversed’ amperometric setup with Ag|AgCl electrode as the working electrode and an ion-selective electrode as the reference one. Advantageously, the proposed approach does not require addition of other chemicals to the sample. A change of primary ions concentration results in change of the potential of the ISE used as the reference electrode and thus in the same change of Ag|AgCl electrode potential in amperometric (potentiostatic) mode. Due to high slope of the current vs. potential dependence for silver / silver chloride electrode small changes of ISE potential …