The State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
Talanta. 2010 Mar 15;80(5):2182-6. doi: 10.1016/j.talanta.2009.11.027. Epub 2009 Nov 13.
A novel and simple method for the direct and quantitative determination of L-tryptophan (Trp), L-tyrosine (Tyr) and L-cysteine (Cys) was proposed in this work. Carbon nanofibers (CNFs), made by electrospinning technique, were used to modify carbon paste electrode (CPE) without any treatment to study the electrochemical behaviors of the three amino acids using cyclic voltammetry (CV) and constant potential amperometric method. The results demonstrated that the CNFs modified carbon paste electrode (CNF-CPE) exhibited high electrocatalytic activity and good analytical performance towards the oxidation of the three amino acids. The linear ranges of Trp, Tyr and Cys were 0.1-119, 0.2-107 and 0.15-64 microM with correlation coefficients of 0.9994, 0.9985 and 0.9996, respectively. All the detection limits of the analytes were 0.1 mM (S/N=3). In addition, the CNF-CPE displayed good reproducibility, high sensitivity and good selectivity towards the determination of the amino acids, making it suitable for the determination of Trp, Tyr and Cys in clinical and medicine.
本工作提出了一种新颖而简单的方法，可直接定量测定 L-色氨酸（Trp）、L-酪氨酸（Tyr）和 L-半胱氨酸（Cys）。通过静电纺丝技术制备的碳纳米纤维（CNFs）无需任何处理即可修饰碳糊电极（CPE），并使用循环伏安法（CV）和恒电位安培法研究了这三种氨基酸的电化学行为。结果表明，CNFs 修饰的碳糊电极（CNF-CPE）对三种氨基酸的氧化具有高电催化活性和良好的分析性能。Trp、Tyr 和 Cys 的线性范围分别为 0.1-119、0.2-107 和 0.15-64 microM，相关系数分别为 0.9994、0.9985 和 0.9996。分析物的所有检测限均为 0.1 mM（S/N=3）。此外，CNF-CPE 对氨基酸的测定具有良好的重现性、高灵敏度和良好的选择性，适用于临床和医学中 Trp、Tyr 和 Cys 的测定。
