细胞色素C在4，5-二氮芴-9-酮修饰玻碳电极上的直接电化学研究

Direct Electrochemical Behavior of Cytochrome C Immobilized on 4,5-Diazafluorene-9-one Modified Glassy Carbon Electrode

采用循环伏安法探讨了细胞色素C(CytC)在4,5-二氮芴-9-酮(dafo)修饰玻碳电极表面的电化学行为。结果表明,CytC在dafo修饰电极上呈现一对峰形较好且准可逆的氧化还原峰,其式电位(E0′)为13mV,峰电流与扫描速度呈线性关系,该电极过程是表面控制过程,电化学反应效率常数(ks)为0.89/s。固定在dafo上的CytC能促进H2O2的催化还原,响应快速而灵敏(<10s),峰电流与H2O2浓度在5.0×10-6～3.0×10-4mol/L范围内呈线性关系;检出限2.5×10-6mol/L;米氏常数为1.07mmol/L,显示出较好的亲和力。

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 KM^app 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 tool/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 eleetrochemical reaction of the redox-active enzyme and the construction of the related enzyme biosensors.