AMPEROMETRIC GLUCOSE SENSORS BASED ON GLUCOSE-OXIDASE IMMOBILIZED IN NAFION

A glucose-sensitive electrode composed of glucose oxidase (GOX) embedded in a layer of the polymer Nafion is described. Electrodes of various configurations on which the layer was cast were tested to determine their response to glucose additions to phosphate buffer and human whole serum samples. These electrodes have good response characteristics and several desirable features. Glucose sensors based on Nafion/GOX layers 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 additions 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.