Use of microperoxidase-11 to functionalize tin dioxide electrodes for the optical and electrochemical sensing of hydrogen peroxide

Abstract

In this paper, we employ microperoxidase MP-11 immobilized on mesoporous SnO 2 electrodes in order to study its peroxidase activity and reaction mechanism. We demonstrate the catalytic redox chemistry of the immobilized MP-11 via direct interfacial electron transfer without the use of electron mediators. By taking advantage from the optical transparency of the SnO 2 electrodes, optical absorbance spectroscopy is used in order to compliment the data information obtained from electrochemical techniques. The catalytic activity of the immobilized MP-11 is found to proceed via the Fenton reaction, yielding OH radical intermediates. We also demonstrate the viability of using this electrode system as a potential H 2O 2 biosensor with a sensitivity range of 0.05–30 μM.