Electrochemical Capacitive K + EMIS Chemical Sensor Based on the Dibromoaza[7]helicene as an Ionophore for Potassium Ions Detection
Résumé
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 Si3N4/SiO2/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+, Cu2+, Ca2+, and Mg2+). 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: Si3N4/SiO2/Si-p/Cu-Al as a transducer.