摘要
以壳聚糖和介孔碳氮材料共混所得复合物为固定漆酶的载体,将固酶复合物滴涂在裸玻碳电极表面并干燥后,得到固定漆酶基阴极。考察了此电极在不含底物的电解质溶液中的直接电化学行为,同时还研究了其对氧气还原反应的催化性能和电极的长期使用性、重现性和力学稳定性。在此基础上还考察了此电极作为氧气电化学传感器的性能。研究结果表明,介孔碳氮材料-壳聚糖固定漆酶修饰电极能在无任何电子中介体条件下,实现漆酶活性中心T1与电极之间的直接电子转移,而且能在较高的电位下实现氧气的电还原。此电极催化氧还原的起始电位约为860 mV,氧还原的半波电流密度约为78×10-6A/cm2。这种漆酶基电极的重现性良好且具有优异的长期稳定性,但力学稳定性较差。此电极对氧的传感性能良好:检测限低达0.4μmol/L,灵敏度高达(67.9×10-6A·L/mmol),具有良好的对氧亲和力(K M=764.0μmol/L)。
This article adopted the composite made up of chitosan and meso-porous carbon doped with nitrogen material which was secured by mechanical mixing as carrier for laccase immobilization. Entrapped laccase based biocathode was prepared by complex with enzyme dripping and coating on the surface of bare glassy carbon electrode and drying process in air consecutively. The direct electrochemical behavior of this as- prepared electrode in the electrolyte without any substrate was investigated, furthermore its catalytic function for oxygen reduction reaction （ORR）, its long-term usability, reproducibility and mechanical stability were systematically estimated. On the basis of previous results, performance of this laccase based electrode as oxygen electrochemical sensor was examined. Results from research indicate that the composite composed of meso-porous carbon doped with nitrogen and chitosan with entrapped enzyme modified electrode displays the direct electron transfer between T1 active centre in laccase and the electrode in the absence of any extra electron relay and can catalyze oxygen electrochemical reduction （ORR） under higher potentials. The onset potential for ORR is -860 mV and the mid-wave current density for ORR is 78×10^-6A/cm2. This laccase based electrode shows excellent reproducibility and desirable long-term stability, but its mechanical stability is inferior. This laccase base electrode was proved to be a suitable sensor for oxygen molecules with the detection limit low to 0. 4μmol/L, the high sensitivity of 67.9×10^-6 A- L/mmol and the preferable affinity KM = 764.0 μmol/L for oxygen.
出处
《应用化学》
CAS
CSCD
北大核心
2013年第10期1194-1201,共8页
Chinese Journal of Applied Chemistry
关键词
漆酶
直接电子迁移
氧还原反应
电化学传感器
Laccase,direct electron transfer,oxygen reduction reaction,electrochemical sensor
