A biosensor based on cytochrome c immobilization on a poly-3-methylthiophene/multi-walled carbon nanotubes hybrid-modified electrode. Application to the electrochemical determination of nitrite
A biosensor based on cytochrome c immobilization on a poly-3-methylthiophene/multi-walled carbon nanotubes hybrid-modified electrode. Application to the electrochemical determination of nitrite
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DOI：
10.1016/j.jelechem.2010.03.025
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发表时间：
2010-05-15
影响因子：
4.5
通讯作者：
Pingarron, J. M.
中科院分区：
文献类型：
--
作者：
Eguilaz, M.;Aguei, L.;Pingarron, J. M.
报道了一种将生物分子固定在导电聚合物聚3甲基噻吩（P3 MT）和多壁碳纳米管（MWCNT）杂化材料上的细胞色素c（Cyt c）电化学生物传感器。将Cyt c固定在L-半胱氨酸（L-Cys）自组装膜修饰的P3 MT/MWCNT/GCE上，在中性pH下，带正电荷的Cyt c与L-Cys带负电荷的位点强烈相互作用。电子转移速率常数k（s）为0.49 +/- 0.01 s（-1），Cyt c的表面覆盖率γ为（1.6 +/- 0.8）x 10（-11）mol cm（-2）。在优化条件下，该无介体生物传感器对H2 O2的还原具有良好的电催化活性。在pH 8.0的0.05 M Tris-HCl缓冲溶液中，在0.0 V的电位下，对H_2O_2的安培法测定具有良好的重复性（RSD = 3.1%，n = 10）和可接受的重现性（RSD = 8.1%，n = 5）。评估了生物传感器的寿命。H2 O2在0.7 ~ 400 μ M范围内呈线性关系（r = 0.998），检出限为0.23 μ M。H2 O2测定的分析特性被认为是优于其他纳米结构的细胞色素c生物传感器的报告。Cyt c与H_2O_2反应的表观米氏常数为451 μ M。将所研制的Cyt c/l-Cys/P3 MT/MWCNT/GCE生物传感器应用于电致[Fe 4 +-Cyt c]物种氧化NO2-生成NO的生物催化测定。在搅拌的PBS溶液中，在+0.9 V的电位下，安培法允许在10和100 μ M之间的线性范围内测定亚硝酸盐，检测限为0.5 μ M。(C)2010 Elsevier B. V.保留所有权利。
A cytochrome c (Cyt c) electrochemical biosensor constructed by immobilization of the biomolecule on a hybrid material consisting of the conducting polymer poly-(3-methylthiophene) (P3MT) and multi-walled carbon nanotubes (MWCNT) is reported. Cyt c was immobilized onto l-cysteine (l-Cys) self-assembled monolayer-modified P3MT/MWCNT/GCE at neutral pH, where positively charged Cyt c strongly interacts with l-Cys negatively charged sites. The electron transfer rate constant, k(s), was 0.49 +/- 0.01 s(-1), and the surface coverage of Cyt c, Gamma, (1.6 +/- 0.8) x 10(-11) mol cm(-2). Under the optimized conditions, the mediatorless biosensor exhibits good electrocatalytic activity towards H2O2 reduction. The amperometric measurements of H2O2 at an applied potential of 0.0 V in 0.05 M Tris-HCl buffer of pH 8.0 exhibited good repeatability (RSD = 3.1%, n = 10) and an acceptable reproducibility for the biosensor preparation (RSD = 8.1%, n = 5). The lifetime of the biosensor was evaluated. A linear calibration graph for H2O2 (r = 0.998) was obtained between 0.7 and 400 mu M, with a detection limit of 0.23 mu M. The analytical characteristics for H2O2 determination were found to be better than those reported for other nano-structured cytochrome c biosensors. The apparent Michaelis-Menten constant for the reaction between Cyt c and H2O2 was 451 mu M. The developed Cyt c/l-Cys/P3MT/MWCNT/GCE biosensor was applied for the biocatalytic determination of nitrite through the oxidation of NO2- to NO; by electrogenerated [Fe4+-Cyt c] species. Amperometry in stirred PBS solutions at a potential of +0.9 V allowed nitrite to be determined in a linear range between 10 and 100 mu M, with a detection limit of 0.5 mu M. (C) 2010 Elsevier B.V. All rights reserved.