• Graphene;
  • Chitosan;
  • Microperoxidase-11;
  • Direct electrochemistry;
  • Hydrogen peroxide;
  • Biosensors;
  • Electron transfer;
  • Biocatalysis


A bioelectrochemical platform has been constructed for the direct electron transfer and biosensing purposes of microperoxidase-11 (MP-11) immobilized on the chitosan dispersed multilayer graphene nanocomposite. The immobilized MP-11 at the modified gold electrode displays a well-defined and quasireversible redox peaks, with a formal potential of −0.38 V/SCE in a buffer solution (pH 7.0). MP-11 absorbed on the electrode surface exhibits high electrocatalytic activity toward the reduction of both oxygen and hydrogen peroxide and also shows good analytical performance for the amperometric detection of H2O2 with a linear range from 2.5 to 135 μM. These results indicate the graphene modified electrode might be used as a third generation biosensor for H2O2 detection.