Thermally stable improved first-generation glucose biosensors based on Nafion/glucose-oxidase modified heated electrodes

We illustrate how the use of heated electrodes enhances the performance of glucose biosensors based on amperometric detection of the glucose-oxidase generated hydrogen peroxide. Nafion is shown to be an excellent matrix to protect glucose-oxidase from thermal inactivation during the heating pulses. The influence of the electrode temperature upon the amperometric response is examined. Temperature pulse amperometry (TPA) has been used to obtain convenient peak-shaped analytical signals. Surprisingly, up to 67.5 °C, the activity of Nafion-entrapped glucose-oxidase is greatly enhanced (24-fold) by accelerated kinetics rather than decreased by thermal inactivation. Amperometric signals even at elevated temperatures are stable upon prolonged operation involving repetitive measurements. The linear calibration range is significantly extended.