Direct spectroelectrochemistry of peroxidases immobilised on mesoporous metal oxide electrodes: Towards reagentless hydrogen peroxide sensing

In this paper, we employ two peroxidases (horseradish peroxidase, HRP and cytochrome c peroxidase, CcP) to demonstrate their ability to retain their redox and biological functions after their immobilisation on mesoporous TiO₂ and SnO₂ electrodes. We will also demonstrate the use of HRP immobilised on the metal oxide electrodes for the development of reagentless optical and electrochemical biosensors for the detection of hydrogen peroxide (H₂O₂) with low detection limit of 0.04 and 1 μM, respectively.