Sensitive electrochemical detection of enzymatically generated thiocholine at carbon nanotube modified glassy carbon electrode
Sensitive electrochemical detection of enzymatically generated thiocholine at carbon nanotube modified glassy carbon electrode
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DOI：
10.1016/j.elecom.2005.08.025
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发表时间：
2005-11-01
影响因子：
5.4
通讯作者：
Lin, YH
中科院分区：
文献类型：
--
作者：
Liu, GD;Riechers, SL;Lin, YH
采用碳纳米管修饰的玻璃碳（CNT/GC）电极提高了酶促硫胆碱电化学测量的灵敏度。比较了硫代胆碱在碳纳米管/气相色谱、玻璃碳、碳糊和金电极上的循环伏安和安培特性。由于碳纳米管末端边缘平面状石墨的电催化活性、快速的电子转移和大的工作表面积，碳纳米管层极大地改善了酶促生成的硫胆碱产物的阳极检测，包括更低的氧化过电位（0.15 V）和更高的灵敏度。根据工作条件对传感器性能进行了优化。在最佳批量条件下，检测限为5 × 10(-6) mol/L，精密度良好（RSD = 5.2%, n = 10）。此外，硫代胆碱在碳纳米管/气相色谱电极上的吸引响应使其能够用于恒电位流注射分析。检出限提高到3 × 10(-7) mol/L。利用碳纳米管传感平台对酶促硫代胆碱进行高灵敏度电化学检测，为制备用于有机磷农药和神经毒剂监测的乙酰胆碱酯酶生物传感器提供了广阔的前景。(c) 2005 Elsevier B.V.版权所有
A carbon nanotube modified glassy carbon (CNT/GC) electrode was used for enhancing the sensitivity of electrochemical measurements of enzymatically generated thiocholine. Cyclic voltammetric and amperometric characteristics of thiocholine at CNT/GC, glassy carbon, carbon paste and gold electrodes were compared. The CNT layer leads to a greatly improved anodic detection of enzymatically generated thiocholine product including lower oxidation overpotential (0.15 V) and higher sensitivity because of electrocatalytic activity of edge-plane-like graphite site at the CNT ends, fast electron transfer and big working surface area. The sensor performance was optimized with respect to the operating conditions. Under the optimal batch conditions, a detection limit of 5 x 10(-6) mol/L was obtained with a good precision (RSD = 5.2%, n = 10). Furthermore, the attractive response of thiocholine on CNT/GC electrode has allowed it to be used for constant-potential flow injection analysis. The detection limit was greatly improved to 3 x 10(-7) mol/L. The high sensitive electrochemical detection of enzymatically generated thiocholine with CNT sensing platform holds great promise to prepare acetylcholinesterase biosensor for monitoring organophosphate pesticides and nerve agents. (c) 2005 Elsevier B.V. All rights reserved.