Design of a stable charge transfer complex electrode for a third-generation amperometric glucose sensor.
Design of a stable charge transfer complex electrode for a third-generation amperometric glucose sensor.
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DOI：
10.1021/ac9510393
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发表时间：
1996-09
影响因子：
7.4
通讯作者：
G. F. Khan;M. Ohwa;W. Wernet
中科院分区：
文献类型：
--
作者：
G. F. Khan;M. Ohwa;W. Wernet
一种制备稳定的黄素蛋白直接氧化电荷转移络合物(CTC)电极的新方法和第三代电流型生物传感器的制造(Koopal，C.G.J.；Feiters，M.C.；Nolte，R.J.M.生物电化学)。生物能源公司。1992、29、159-175)系统。四硫富瓦烯-四氰基喹二甲烷(TTF-TCNQ)是一种有机CTC，它被生长在可成形的导电(SEC)膜(一种多阴离子掺杂的聚吡咯薄膜)的表面，使得树状晶体结构垂直地矗立在表面。葡萄糖氧化酶(GOx)被戊二醛吸附并交联，固定在CTC结构的表面。晶体之间的空隙中填充了交联明胶，以确保树状晶体结构的稳定性以及酶的稳定性。由于酶在CTC表面的亲和性和良好的定向性，酶直接在晶面被氧化，这使得葡萄糖传感器的性能得到了显著的改善。它工作在0.0V至0.25V(vs Ag/AgCl)的电压范围内。在0.25V时，最大电流密度达到1.8 mA/cm2，线性范围扩大。正常缓冲溶液中的氧气对传感器输出影响不大。由生理液体中包含的干扰引起的电流可以忽略不计。传感器的工作寿命和保质期大大延长。该传感器在0.1V连续极化的流动注射系统中连续使用，样品(通常为10 mM葡萄糖)以30分钟的间隔进样。连续使用100天后，当前产量降至初始水平的40%。当传感器在冷冻箱中干燥保存一年后，没有观察到传感器输出的变化。报道了该体系的电化学速率常数和有效米氏常数。
A novel approach to prepare a stable charge transfer complex (CTC) electrode for the direct oxidation of flavoproteins and the fabrication of a third generation amperometric biosensor (Koopal, C.G.J.; Feiters, M.C.; Nolte, R.J.M. Bioelectrochem. Bioenerg. 1992, 29, 159-175) system is described. Tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ), an organic CTC, is grown at the surface of a shapable electroconductive (SEC) film (a polyanion-doped polypyrrole film) in such a way that it makes a tree-shaped crystal structure standing vertically on the surface. Glucose oxidase (GOx) is adsorbed and cross-linked with glutaraldehyde to fix at the surface of the CTC structure. The space between crystals is filled with cross-linked gelatin to ensure the stability of the treelike crystal structure as well as the stability of the enzyme. Because of the close proximity and the favorable orientation of the enzyme at the CTC surface, the enzyme is directly oxidized at the crystal surface, which leads to a glucose sensor with remarkably improved performance. It works at a potential from 0.0 to 0.25 V (vs Ag/AgCl). The maximum current density at 0.25 V reaches 1.8 mA/cm2, with an extended linear range. The oxygen in the normal buffer solution has little effect on the sensor output. The current caused by interference contained in the physiological fluids is negligible. The working life as well as the shelf life of the sensor is substantially prolonged. The sensor was continuously used in a flow injection system with a continuous polarization at 0.1 V, and the samples (usually 10 mM glucose) were injected at 30 min intervals. After 100 days of continuous use, the current output dropped to 40% of the initial level. No change in the output of the sensor was observed over a year when the sensor was stored dry in a freezer. The electrochemical rate constants and the effective Michaelis constant of the system are reported.