POTASSIUM ION-SELECTIVE ELECTRODES BASED ON VALINOMYCIN PVC OVERLAYERED SOLID SUBSTRATES

In this work, permutations of plasticized PVC membranes with incorporated valinomycin are coated over various substrate metallizations. Characterization of the resulting potassium electrodes includes measurement of sensitivity, short- and long-term potential drift, dissolved oxygen induced potential transients and probe lifetime. Results using the best performing metallizations compare favorably with those obtained using identical membranes in the symmetrical solution contact configuration. Prospects for use of this approach as the ion-sensing layer of ISFET (Ion-Sensitive Field-Effect Transistor) devices are considered.