Planar amperometric glucose sensor based on glucose oxidase immobilized by chitosan film on Prussian blue layer

A planar amperometric glucose microsensor based on glucose oxidase immobilized by chitosan film on Prussian Blue layer has been developed. The experimental results show that the optimum detection potential is 50 mV ( versus Ag/AgCl) and the optimum pH is 6.5. Under the selective conditions the sensor exhibits excellent sensitivity of 98 nA/M and a linear range of 0.1-6.0 mM. The apparent Michanelis-Menten constant of the sensor is 21 mM. The response time is less than 60 seconds. No apparent change in the response to glucose was observed during one month. Foremost, the interference of ascorbic and uric acids can be avoided due to selective permeability of chitosan film and electrocatalysis of PB layer to H2O2. The sensor has been applied to detect glucose in human blood serum.