Direct Electrochemical Behavior of Cytochrome C Immobilized on 4,5-Diazafluorene-9-one Modified Glassy Carbon Electrode
The direct electrochemical behavior of cytochrome C(Cyt C) immobilized on 4,5-diazafluorene-9-one(dafo) modified glassy carbon electrode was investigated by cyclic voltammetry(CV).The results show that a pair of well-defined quasi-reversible redox peaks of Cyt C was obtained at Cyt C/dafo/GCE based enzyme electrode by the direct electron transfer between the protein and the electrode.The peak current was linearly dependent on the scan rate,which indicated that the direct electrochemical characteristics of Cyt C in that case was a surface-controlled process.The immobilized Cyt C could retain bioactivity and catalyze the reduction of glucose in air-saturated solution with the apparent Michaelis-Menten constant KappM of 1.07 mmol/L,the response is fast and sensitive(10 s),and the ampere response has a linear relationship with concentration of H2O2 in the range of 5.0×10-6～-3.0×10-4 mol/L,and detection limit is 2.5×10-6 mol/L.These indicated that 4,5-diazafluorene-9-one was a good candidate material for the direct electrochemical reaction of the redox-active enzyme and the construction of the related enzyme biosensors.