An electrocatalytic glucose sensor for in-vivo application.

An electrocatalytic sensor was developed for continuous measurement of glucose in circulating blood. The sensor is constructed as a flow-through cell that can be integrated into a blood vessel. The principle of measurement is based on the electrochemical oxidation of glucose at an active noble metal electrode. Selectivity is achieved by covering the sensing electrode with a diffusion-limiting membrane and by analyzing the impedance of the electrode/membrane system. The real and the imaginary parts of the impedance at certain potentials are directly proportional to the glucose concentration in the blood. These parameters are used in calculating the blood glucose concentration. To test the sensor, an in-vivo experiment was conducted in a sheep. The sensor's performance remained reliable 71 days after its implantation.