Diffusion coefficients of oxygen, hydrogen peroxide and glucose in a hydrogel

For the design of a new glucose sensor, a knowledge of the diffusion of all participating compounds is needed. A rotating disc electrode covered with hydrogel layer was used to determine the effective diffusion coefficients (Deff) of oxygen, hydrogen peroxide and hydroquinone in a hydrogel, which is used in the sensor. Measurements were carried out under steady-state conditions. The three compounds appeared to be slowed by the gel to the same extent. A comparison was made between the Deff values of glucose and hydroquinone by simultaneous diffusion through a hydrogel membrane. In this case glucose diffusion was slowed to a larger extent than hydroquinone diffusion. The effect, however, was independent of the degree of cross-linking of the hydrogel.