Selective Ion Detection with Integrated Organic Electrochemical Transistors

Abstract Accurate sensing of ion concentrations in body fluids is of importance to monitor cell functions, and any deviation of the concentration serves as a warning sign of pathophysiological conditions. Here, a fabrication approach for an integrated device consisting of two electrochemical transistors, capable of selective simultaneous detection between potassium and sodium ions in an analyte is demonstrated. A common in‐plane gate electrode is integrated in the substrate, enabling the fabrication of micro‐scale ion sensors for biomedical applications. The approach is versatile and can be extended to include numerous ion‐selective transistors on a chip in order to meet the demand for simultaneous sensing of multiple ions.