Zhang Lin, Xu Chunli, Liu Cunwei, Li Baoxin
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Anal Chim Acta. 2014 Jan 27;809:123-7. doi: 10.1016/j.aca.2013.11.043. Epub 2013 Nov 28.
A simple protocol to distinguish enantiomers is extremely intriguing and useful. In this study, we propose a low-cost, facile, sensitive method for visual chiral recognition of enantimers. It is based on the inherent chirality of gold nanoparticles (AuNPs), and the unmodified AuNPs are used as chiral selector for D- and L-Tryptophan (Trp). In the presence of D-Trp, an appreciable red-to-blue color change of AuNPs solution can be observed, whereas no color change is found in the presence of L-Trp. The method can be used to detect D-Trp in the range of 0.2-10 μM, and the limit of detection is 0.1 μM. The chiral assay described in this work is easily readout with the naked eye or using a UV-vis spectrometer. Furthermore, the AuNPs can selectively adsorb D-Trp, and simple centrifugation can allow the precipitation of D-Trp with AuNPs and leave a net excess of the other enantiomer in solution, thus resulting in enantioseparation. In this method, AuNPs do not need any labeling or modifying with chiral molecules. The method is more attractive because of its high sensitivity, low cost, ready availability and simple manipulation.
一种区分对映体的简单方法极具吸引力且十分有用。在本研究中，我们提出了一种低成本、简便、灵敏的可视化对映体手性识别方法。该方法基于金纳米粒子（AuNPs）的固有手性，未修饰的AuNPs被用作D-和L-色氨酸（Trp）的手性选择剂。在D-Trp存在的情况下，可以观察到AuNPs溶液有明显的从红色到蓝色的颜色变化，而在L-Trp存在时则未发现颜色变化。该方法可用于检测浓度范围为0.2 - 10 μM的D-Trp，检测限为0.1 μM。本文所述的手性检测方法可用肉眼或紫外可见光谱仪轻松读出。此外，AuNPs可以选择性地吸附D-Trp，简单的离心操作可以使D-Trp与AuNPs一起沉淀，而溶液中另一种对映体则有净过量，从而实现对映体分离。在该方法中，AuNPs不需要用手性分子进行任何标记或修饰。由于其高灵敏度、低成本、易于获得和操作简单，该方法更具吸引力。
