AMPEROMETRIC GLUCOSE SENSORS BASED ON GLUCOSE-OXIDASE IMMOBILIZED IN NAFION

A glucose-sensitive electrode composed of glucose oxidase (GOX) embedd ed in a layer of the polymer Nafion is described. Electrodes of variou s configurations on which the layer was cast were tested to determine their response to glucose additions to phosphate buffer and human whol e serum samples. These electrodes have good response characteristics a nd several desirable features. Glucose sensors based on Nafion/GOX lay ers cast onto platinum electrodes respond to glucose additions with a rapid response time (2 to 4 seconds), have a long lifetime when stored in a phosphate buffer (55 days before termination of testing), have a reduced sensitivity to local oxygen tension, respond linearly to addi tions of glucose to the serum, and are not fouled by exposure to blood . The Nafion confers some permselectivity on the layer, thus providing a degree of discrimination against anionic interferents.