In this work, we prepared gold nanoparticles (AuNPs) by employing gluconic acid (GlcA) as reducing-cum-stabilizing agent. The proposed GlcA-AuNPs successfully worked as a colorimetric sensor for visual chiral recognition of aromatic amino acid enantiomers, namely tyrosine (d/l-Tyr), phenylalanine (d/l-Phe), and tryptophan (d/l-Trp). After adding L-types to GlcA-AuNPs solution, the color of the mixture changed from red to purple (or gray), while no obvious color change occurred on the addition of D-types. The effect can be detected by naked eyes. The particles have been characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy, zeta potential, the dynamic light scattering analysis as well as UV–Vis spectroscopy. This assay can be used to determine the enantiomeric excess of l-Trp in the range from 0 to + 100%. The method has advantages in simplicity, sensitivity, fast response, and low cost.

在这项工作中，我们通过使用葡萄糖酸 (GlcA) 作为还原兼稳定剂制备了金纳米粒子 (AuNPs)。所提出的 GlcA-AuNPs 成功地用作视觉手性识别芳香族氨基酸对映体的比色传感器，即酪氨酸 ( d/l -Tyr)、苯丙氨酸 ( d/l -Phe) 和色氨酸 ( d/l-Trp）。在 GlcA-AuNPs 溶液中加入 L 型后，混合物的颜色由红色变为紫色（或灰色），而加入 D 型时没有发生明显的颜色变化。效果可以用肉眼检测。通过透射电子显微镜、傅里叶变换红外光谱、zeta 电位、动态光散射分析以及紫外-可见光谱对颗粒进行了表征。该测定可用于确定0 至 + 100% 范围内的l -Trp对映体过量。该方法具有简便、灵敏、响应快、成本低的优点。