An amperometric biosensor based on the coimmobilization of horseradish peroxidase and methylene blue on a β-type zeolite modified electrode

A new biosensor for the amperometric detection of hydrogen peroxide was developed based on the co-immobilization of horseradish peroxidase (HRP) and methylene blue on a β-type zeolite modified glassy carbon electrode without the commonly used bovine serum albumin-glutaraldehyde. The intermolecular interaction between enzyme and zeolite matrix was investigated using FT-IR. The cyclic voltammetry and amperometric measurement demonstrated that methylene blue co-immobilized with HRP in this way displayed good stability and could efficiently transfer electrons between immobilized HRP and the electrode. The sensor responded rapidly to H 2 O 2 in the linear range from 2.5 × 10 –6 to 4.0 × 10 –3 M with a detection limit of 0.3 μM. The sensor was stable in continuous operation.