Maleki N, Safavi A, Sedaghati F, Tajabadi F
Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Fars 71454, Iran.
Anal Biochem. 2007 Oct 15;369(2):149-53. doi: 10.1016/j.ab.2007.04.024. Epub 2007 Apr 25.
The electrochemistry of L-cysteine (CySH) in neutral aqueous media was investigated using carbon ionic liquid electrode (CILE). Comparative experiments were carried out using glassy carbon electrodes. At CILE, highly reproducible and well-defined cyclic voltammograms were obtained for l-cysteine with a peak potential of 0.49V vs Ag/AgCl, showing that CILE manifests a good electrocatalytic activity toward oxidation of l-cysteine. A linear dynamic range of 2-210microM with an experimental detection limit of 2microM was obtained. The method was successfully applied to the determination of l-cysteine in a sample of soya milk. Cysteine oxidation at CILE does not result in deactivation of the electrode surface. Mechanistic studies showed that, at CILE, the overall CySH oxidation is controlled by the oxidation of the CyS(-) electroactive species.
使用碳离子液体电极（CILE）研究了L-半胱氨酸（CySH）在中性水性介质中的电化学性质。使用玻碳电极进行了对比实验。在CILE上，L-半胱氨酸获得了高度可重现且定义明确的循环伏安图，相对于Ag/AgCl的峰电位为0.49V，表明CILE对L-半胱氨酸的氧化表现出良好的电催化活性。获得了2-210μM的线性动态范围，实验检测限为2μM。该方法成功应用于豆浆样品中L-半胱氨酸的测定。CILE上的半胱氨酸氧化不会导致电极表面失活。机理研究表明，在CILE上，CySH的整体氧化受CyS(-)电活性物种的氧化控制。
