血红蛋白在二氧化铈修饰电极上的直接电化学

Direct Electrochemistry of Hemoglobin Immobilized on Electrode Modified by Ceria

将二氧化铈(CeO2)与酶复合修饰电极,采用循环伏安法研究了血红蛋白(Hb)在CeO2修饰的玻碳电极上的电化学行为.实验表明,固定在CeO2材料上的Hb,不仅能有效地与电极表面进行直接电子转移,而且能够保持其生物催化活性.制得的Nafion/CeO2/Hb/GC修饰电极的电子传递速率ks为(0.68±0.09)s-1,对H2O2的检测限为1.013μmol·L-1,重现性和稳定性较好.CeO2在实验中体现出一定的生物相容性,起到了促进Hb与电极之间进行直接电子传递的作用.CeO2修饰电极进行蛋白质直接电化学测定以及酶生物电催化的成功实践,为稀土氧化物材料在电化学传感领域中的应用开辟了思路.

This study described the bioelectrochemistry of hemoglobin （Hb） immobilized on GC electrode modified by ceria （CeO2）. The characteristics of Hb/CeO2/Nafion/GC electrode were studied by using electrochemical methods. Hb immobilized on Nafion-CeO2 film retained its native secondary structure, achieved direct electron transfer with the apparent heterogeneous electron transfer rate constant （ks） of （0.68±0.09） s-1 and showed excellent bioelectrocatalytic activity to the reduction of hydrogen peroxide. The electrocatalytic response of the biosensor varied linearly with the H2O2 concentration ranging from 2.45 to 19.6 μmol· L^-1, with a detection limit of 1.013 μmol·L^-1 and good long-term stability. In the experiment, CeO2 showed an excellent biocompatibility and provided a friendly microenvironment for the electron transfer between Hb and GC. The successful practice of CeO2 modified electrode for the direct electrochemical analysis of proteins and the bioelectrocatalytic activity of enzymes offers an efficient strategy and a new promising platform for the applications of rare earth oxide materials in the field of electrochemical sensors.