Chen Yu, Yang Xiao-Jing, Guo Li-Rong, Li Jing, Xia Xing-Hua, Zheng Li-Min
State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
Anal Chim Acta. 2009 Jun 30;644(1-2):83-9. doi: 10.1016/j.aca.2009.04.027. Epub 2009 Apr 24.
Multilayered hemoglobin (Hb) molecules were successfully immobilized on three-dimensional gold film electrode modified with self-assembled monolayers (SAMs) of 3-mercaptopropylphosphonic acid. Direct electrochemistry of the immobilized multilayered Hb occurs with high thermal stability and electrochemical stability. In the multilayered Hb film, the most inner Hb molecules can directly transfer electron with the electrode, while the Hb protein beyond this layer communicates electron with the electrode via protein-protein electron exchange. In addition, the proposed functional interface can greatly enhance electron transfer rate of the immobilized Hb protein (k(s) = 15.8 +/- 2.0 s(-1)) due to the increase of roughness of the gold substrate. Under optimized experimental conditions, the multilayered Hb film displays good bioelectrocatalytic activity toward the reduction of hydrogen peroxide. This electrochemical sensor shows fast response (less than 1 s), wide linear range (7.8 x 10(-8) to 9.1 x 10(-5) M) and low detection limit (2.5 x 10(-8) M), which can be attributed to good mass transport, large Hb proteins loading per unit area and fast electron transfer rate of Hb protein.
多层血红蛋白（Hb）分子成功固定在由3-巯基丙基膦酸自组装单分子层（SAMs）修饰的三维金膜电极上。固定化多层Hb的直接电化学具有高热稳定性和电化学稳定性。在多层Hb膜中，最内层的Hb分子可直接与电极进行电子转移，而该层之外的Hb蛋白则通过蛋白质-蛋白质电子交换与电极进行电子传递。此外，由于金基底粗糙度的增加，所提出的功能界面可极大地提高固定化Hb蛋白的电子转移速率（k(s) = 15.8 +/- 2.0 s(-1)）。在优化的实验条件下，多层Hb膜对过氧化氢的还原显示出良好的生物电催化活性。该电化学传感器响应快速（小于1秒）、线性范围宽（7.8 x 10(-8)至9.1 x 10(-5) M）且检测限低（2.5 x 10(-8) M），这可归因于良好的传质、单位面积上大量的Hb蛋白负载以及Hb蛋白快速的电子转移速率。
