Electrochemical Capacitive K + EMIS Chemical Sensor Based on the Dibromoaza[7]helicene as an Ionophore for Potassium Ions Detection

A K + ‐sensitive capacitive electrolyte‐membrane‐insulator‐semiconductor (EMIS) based on a novel dibromoaza[7]helicene ionophore has been developed. An ion‐sensitive membrane based on polyvinylchloride (PVC) doped with the ionophore was deposited on the Si 3 N 4 /SiO 2 /Si‐p/Cu‐Al transducer. The properties of the K + ‐EMIS chemical sensor were investigated by electrochemical impedance spectroscopy (EIS). All the developed devices upon being tested have shown good sensitivity and linearity responses within the range 10 −6 M to 10 −1 M of potassium activity, with good selectivity over a wide variety of other cations (Na + , Li + , Cu 2+ , Ca 2+ , and Mg 2+ ). To our knowledge, this is the first time that a capacitive field‐effect sensor has been fabricated using helicene as a carrier for K + ‐detection, combined with the structure: Si 3 N 4 /SiO 2 /Si‐p/Cu‐Al as a transducer.