Functionalized inorganic-organic composite material derivated by sol-gel for construction of mediated amperometric hydrogen peroxide biosensor

A novel functionalized inorganic-organic hybrid material with cation exchan ge property was prepared by sol-gel method. The H2O2 biosensor was fabricat ed by simply dipping the horseradish peroxidase-containing functionalized m embrane modified electrode into Meldola's blue (MDB) solution. MDB was adso rbed and firmly immobilized within the membrane. The electrochemical behavi or of MDB incorporated in the membrane was more reversible compared with th at of the solution species and suitable as mediator for the horseradish per oxidase. The response time was less than 25 s. Linear range is up to 0.6 mM (COH. coeff. 0.9998) with detection Limit of 9 x 10(-7) M. High sensitivit y of 75 nA mu M cm(-2) was obtained due to high MDB-loading. The biosensor exhibited a good stability. (C) 1999 Elsevier Science B.V. All rights reser ved.