Functionalized inorganic–organic composite material derivated by sol–gel for construction of mediated amperometric hydrogen peroxide biosensor Original Research Article

A novel functionalized inorganic–organic hybrid material with cation exchange property was prepared by sol–gel method. The H2O2 biosensor was fabricated by simply dipping the horseradish peroxidase-containing functionalized membrane modified electrode into Meldolaʹs blue (MDB) solution. MDB was adsorbed and firmly immobilized within the membrane. The electrochemical behavior of MDB incorporated in the membrane was more reversible compared with that of the solution species and suitable as mediator for the horseradish peroxidase. The response time was less than 25 s. Linear range is up to 0.6 mM (Corr. coeff. 0.9998) with detection limit of 9×10−7 M. High sensitivity of 75 nA μM cm−2 was obtained due to high MDB-loading. The biosensor exhibited a good stability.