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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)。
The complex of chitosan and mesoporous carbon-nitrogen material was used as a carrier for immobilizing laccase. The immobilized enzyme complex was applied to the surface of the bare glassy carbon electrode and dried to obtain a fixed laccase-based cathode. The direct electrochemical behavior of the electrode in electrolyte solution without substrate was investigated. The catalytic performance of the electrode for oxygen reduction and the long-term use, reproducibility and mechanical stability of the electrode were also studied. On this basis, we also investigated the performance of this electrode as an oxygen electrochemical sensor. The results show that the immobilized laccase immobilized on mesoporous carbon-nitrogen material-chitosan can realize the direct electron transfer between the laccase active center T1 and the electrode without any electron mediator, and at the higher potential Under the oxygen to achieve the electrical reduction. The initial potential of this electrode for catalytic oxygen reduction is about 860 mV, and the half-wave current density of oxygen reduction is about 78 × 10 -6 A / cm 2. This Laccase-based electrode has good reproducibility and excellent long-term stability but poor mechanical stability. The electrode has good oxygen sensing performance: the detection limit is as low as 0.4μmol / L and the sensitivity is as high as (67.9 × 10-6A · L / mmol) with good oxygen affinity (K M = 764.0μmol / L).