Direct electrochemistry transfer and electrocatalysis of hemoglobin immobilized in porous Mn₂O₃

Novel porous Mn₂O₃ with good crystallinity was synthesized via hard-template method. Hb-Mn₂O₃ nanocomposite was prepared and used for biosensor construction. The Hb-Mn₂O₃-Nafion modified electrode shows fast direct electron transfer and displays good electrocatalytic response to the reduction of H₂O₂. The response time is less than 5 s, the sensitivity is as high as 493 μA·L·mmol^-1·cm^-2 in a linear range of 1-100 μmol/L, and the detection limit is 0.16 μmol/L. This modified electrode also shows good stability and reproducibility. This indicates that the porous Mn₂O₃ provides a good matrix for enzyme immobilization and biosensor construction.