Hydrogen peroxide biosensor based on sol–gel-derived glasses doped with Eastman AQ polymer Original Research Article

A hydrogen peroxide biosensor based on sol–gel-derived glasses doped with poly(ester sulfonic acid) Eastman AQ 55D was constructed. Thionine (TH), as a mediator, was incorporated in this matrix by electrostatic force between TH+ and the negatively charged sulfonic acid group in Eastman AQ polymer. Performance and characteristics of the sensor were evaluated with respect to response time, sensitivity and storage stability. The enzyme electrode has a sensitivity of 11.36 μA mM−1 with a detection limit of 5.0×10−7 M H2O2, and the sensor achieved 95% of the steady state current within 20 s.