Zhang Ling, Zhang Qian, Lu Xianbo, Li Jinghong
Department of Chemistry, Key Lab of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China.
Biosens Bioelectron. 2007 Aug 30;23(1):102-6. doi: 10.1016/j.bios.2007.03.015. Epub 2007 Mar 30.
Intercalation of horseradish peroxidase (HRP) into layered titanate by assembling it with titanate nano-sheets (TNS) was firstly used for fabrication of enzyme electrode (HRP-TNS electrode). XRD result revealed that HRP-TNS film featured layered structure with HRP monolayer intercalated between the titanate layers. UV-vis spectra result indicated the intercalated HRP in TNS film well retained its native structure. The HRP-TNS film was uniform with porous structures which were confirmed by SEM. The immobilized HRP in the TNS film exhibited fast direct electron transfer and showed a good electrocatalytic performance to H2O2 with high sensitivity, wide linear range and low detection. The excellent electrochemical performance of the HRP-TNS electrode was attributed to biocompatibility of the titanate sheets, porous architectures of the HRP-TNS film which retained activity of HRP to large extent, avoided aggregation of HRP, provided better mass transport and allowed more HRP loading per unit area. Thus, the simple method described here provides a novel and effective platform for immobilization of enzyme in realizing direct electrochemistry and has a promising application in fabrication of the third-generation electrochemical biosensors.
通过将辣根过氧化物酶（HRP）与钛酸盐纳米片（TNS）组装，首次将HRP插入层状钛酸盐中用于制备酶电极（HRP-TNS电极）。X射线衍射结果表明，HRP-TNS膜具有层状结构，HRP单层插层在钛酸盐层之间。紫外可见光谱结果表明，TNS膜中插层的HRP很好地保留了其天然结构。SEM证实HRP-TNS膜均匀且具有多孔结构。TNS膜中固定化的HRP表现出快速的直接电子转移，对H2O2具有良好的电催化性能，具有高灵敏度、宽线性范围和低检测限。HRP-TNS电极优异的电化学性能归因于钛酸盐片的生物相容性、HRP-TNS膜的多孔结构，该结构在很大程度上保留了HRP的活性，避免了HRP的聚集，提供了更好的传质，并允许每单位面积负载更多的HRP。因此，本文所述的简单方法为酶的固定化提供了一个新颖有效的平台，以实现直接电化学，在第三代电化学生物传感器的制备中具有广阔的应用前景。
