Miniaturised all-solid-state potentiometric ion sensors based on PVC-membranes containing conducting polymers

The paper presents the design of all-solid-state potassium microsensors for flow analysis. The sensors are based on Ag planar electrodes as transducers (without internal electrolyte or poly(2-hydroxyethyl methacrylate) (polyHEMA) layer) and ion-selective membranes with the addition of conducting polymers doped with organic acids. The performance of the microsensors containing three conducting polymers: polyaniline (PANI), polyanisidine (PANIZ), and polypyrrole (PPy) in a membrane were determined. The best results, i.e. the highest potassium selectivity in comparison with the sensors based on internal electrolyte immobilized in polyHEMA layer and good signal stability (significantly better than for sensors without the addition of conducting polymers) were obtained for microsensors containing polypyrrole in plasticized PVC membranes.