Towards the conception of an amperometric sensor of L-tyrosine based on Hemin/PAMAM/MWCNT modified glassy carbon electrode
Towards the conception of an amperometric sensor of L-tyrosine based on Hemin/PAMAM/MWCNT modified glassy carbon electrode
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DOI：
10.1016/j.electacta.2010.06.003
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发表时间：
2010-09-01
影响因子：
6.6
通讯作者：
Tang, Tiantian
中科院分区：
文献类型：
--
作者：
Ma, Qiang;Ai, Shiyun;Tang, Tiantian
将氯化血红素固定在聚酰胺-胺/多壁碳纳米管（PAMAM/MWCNT）纳米复合膜修饰玻碳电极（GCE）上，制备了一种新型的电流型传感器。采用电化学阻抗谱（EIS）、循环伏安（CV）和紫外可见吸收光谱（UV-vis）等方法研究了固定化氯化血红素的可能存在状态和电化学活性。在Hemin/PAMAM/MWCNT纳米复合膜中，MWCNT层具有优良的固有导电性，提高了电子传递速率，而PAMAM层的存在大大提高了修饰电极上Hemin（Gamma）的表面平均浓度。因此，纳米复合膜对L-酪氨酸的氧化表现出更强的电催化活性。研究了修饰电极的动力学参数。在pH7.0的磷酸盐缓冲溶液（PBS）中，该传感器的线性范围为0.1 μ M ~ 28.8 μ M，检测限为0.01 μ M，灵敏度为0.31 μ A μ M ~（-1）cm ~（-2）。此外，L-酪氨酸传感器的响应时间小于5s。该传感器的优异性能主要归因于电生成的高活性氧代铁（IV）卟啉（O = Fe-IV-P）有效地催化L-酪氨酸的氧化。本文提出了一种机制，用于催化氧化L-酪氨酸的铁（IV）卟啉配合物。(C)2010爱思唯尔有限公司版权所有。
A novel amperometric sensor was fabricated based on the immobilization of hemin onto the poly (amidoamine)/multi-walled carbon nanotube (PAMAM/MWCNT) nanocomposite film modified glassy carbon electrode (GCE). Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and ultraviolet visible (UV-vis) adsorption spectroscopy were used to investigate the possible state and electrochemical activity of the immobilized hemin. In the Hemin/PAMAM/MWCNT nanocomposite film, MWCNT layer possessed excellent inherent conductivity to enhance the electron transfer rate, while the layer of PAMAM greatly enlarged the surface average concentration of hemin (Gamma) on the modified electrode. Therefore, the nanocomposite film showed enhanced electrocatalytical activity towards the oxidation of L-tyrosine. The kinetic parameters of the modified electrode were investigated. In pH 7.0 phosphate buffer solution (PBS), the sensor exhibits a wide linear range from 0.1 mu M to 28.8 mu M L-tyrosine with a detection limit of 0.01 mu M and a high sensitivity of 0.31 mu A mu M-1 cm(-2). In addition, the response time of the L-tyrosine sensor is less than 5s. The excellent performance of the sensor is largely attributed to the electro-generated high reactive oxoiron (IV) porphyrin (O = Fe-IV-P) which effectively catalyzed the oxidation of L-tyrosine. A mechanism was herein proposed for the catalytic oxidation of L-tyrosine by oxoiron (IV) porphyrin complexes. (C) 2010 Elsevier Ltd. All rights reserved.