ION SENSING WITH POLY(PYRROLE) BASED MEMBRANES -COMPARISON BETWEEN AMPEROMETRIC AND POTENTIOMETRIC OPERATION MODE

摘要

Easy to obtain conducting polymer films with coupled electronic and ionic conductivity are potentially highly useful for potentiometric and amperometric ion sensors construction. The advantages and limits of analytical potentiometry with poly(pyrrole) films are briefly summarized and contrasted to the amperometric mode of ion sensing. The current recorded under amperometric conditions is related to the ions transport through the polymer / solution interface and under carefully selected experimental conditions it can be proportional to the concentration of the electrolyte ions in the solution. The experimental conditions were optimized in order to obtain analytically useful, broad range of dependencies current vs. concentration. For KCl model solution used the linear responses range was from 10~(-5) up to 3 mol/1.