Development of Biosensors Based on Immobilization of Enzymes in Eastman AQ Polymer Coated with a Layer of Nafion

Abstract
A fast and simple procedure to prepare enzyme electrode is presented herein. A blend of amorphous polyester cationic exchangers (AQ 29D:AQ 55D; ratio 1:1) dispersed in water has been used for the immobilization of l-amino acid, choline, galactose or glucose oxidase enzymes at the surface of a platinum electrode. The resulting polymer-enzyme film was covered by a thin layer of Nafion to avoid its subsequent dissolution in water. The assays are based on the electrochemical detection of enzymatically generated hydrogen peroxide. Good amperometric responses were obtained with each of these enzyme electrodes. The major advantage in using this water dispersed polymer lies in its ability to dissolve the enzyme without any significative loss of enzymatic activity.