Promotion Effects of CNTs-MnO₂ Nanowires-composite on Direct Electron Transfer of Hemoglobin for Amperometric H₂O₂ Determination

摘要

MnO2 nanomaterials with controlled morphologies were synthesized by different methods andcharacterized by SEM, XRD. The promotion ability of as-prepared MnO2 nanomaterials towards thedirect electron transfer (DET) of hemoglobin has been studied. It is found that promotion effect ofcarbon nanotubes (CNTs) and MnO2 nanowires nanocomposite can be observed for the DET ofhemoglobin. In the optimum conditions, the symmetrical redox peak can be observed with peakseparation of 58 mV and formal potential of -0.339 V, respecting the direct electron transfer ofhemoglobin on this composite film. The rate constant has also been estimated to be 1.10 s-1. Theproposed biosensor has favorable reproducibility, stability and sensitivity, and has been used toamperometric determination of hydrogen peroxide with detection limit of 2.4×10-8 mol/L, and theMichealis-Menten constant can also be estimated to be 0.32 mmol/L.