Coated amperometric electrode arrays for multicomponent analysis

This paper describes a sensor array of several amperometric electrodes, each coated with a different permselective film. Coatings with different transport properties, based on size (cellulose acetate), charge (Nafion, poly(vinylpyridine), poly(ester sulfonic acid], and polarity (phospholipid) are employed in connection with a four-electrode thin-layer flow detector. With equipotential operation, the array's response pattern of each analyte provides a unique characterization of the individual components. Multicomponent analysis is obtained by taking advantage of the partial selectivity of the individual sensors and using a pattern recognition (multiple linear regression) method. Additional information is obtained by recording the complete hydrodynamic voltammogram at the individual sensors. The merits of the new array are illustrated for the quantification of neurologically significant catechol compounds.