Reference Free Ion-Selective Electrode For Sensing Potassium Ions

Abstract

Potassium concentration in the blood plays a critical role for the vast population of patients suffering from chronic kidney disorders. Continuous monitoring of blood potassium is essential to lower down the related risks. A homecare-based miniaturized measurement kit would improve patient safety and reduce healthcare costs. Currently, ion-selective electrodes (ISEs) are evolving for the application of blood potassium monitoring. Conventional ISEs are either potentiometric or conductometric. A reference electrode is needed for conventional ISEs to compare the change in ion concentration. These reference electrodes drift over time due to inappropriate filling solution, junction clogging, and leaking, thus, limiting the longevity of the sensors. In this paper, we developed a reference-free solid-state ISE using impedance-based measurement for sensing potassium ions to overcome the issue of drifting. The sensitivity and selectivity of the potassium selective membrane on the gold interdigitated electrode are evaluated using impedance measurement. The developed ISE is scanned with cyclic voltage in potassium solution (KC1) at various concentrations. Also, the longevity of the proposed potassium selective electrode is evaluated by storing the electrodes in 1 mM KC1 solution for 40 days. Thus, the miniaturized potassium selective electrode can assist those patients with the need for continuous monitoring of blood potassium levels.