Bai Ruining, Ma Yuchan, Gao Xinyue, Obaid Essam A M S, Yang Jin, Ouyang Hui, Guo Ting, Fu Zhifeng
Key Laboratory of Luminescence Analysis and Molecular Sensing (Ministry of Education), College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
Anal Chem. 2024 Dec 17;96(50):20139-20146. doi: 10.1021/acs.analchem.4c06219. Epub 2024 Dec 5.
Facile chiral discrimination without relying on chromatographic techniques has long been a huge challenge due to the minimal differences in the physicochemical properties of enantiomers. Polysaccharide hydrogels with natural chiral selectivity can be promising materials for constructing chiral discrimination platforms. In this study, l-cysteine-induced cobalt nanoclusters (LC-CoNCs) were prepared and utilized as chiral nanozymes for promoting the chemiluminescent (CL) signal of a luminol-HO system. Based on the competitive affinity of LC-CoNCs and carnitine enantiomers on a Ca crosslinked sodium alginate (SA) hydrogel interface, a CL method was established for the effective discrimination of carnitine enantiomers. With this strategy, d-carnitine led to a significantly inhibited CL signal, whereas l-carnitine did not exhibit an inhibition effect on the CL signal. According to the results of density functional theory calculations and contact angle measurements, the hydrogel shows an affinity sequence of d-carnitine > LC-CoNCs > l-carnitine due to the synergistic effect of SA and Ca, which is the foundation for achieving effective discrimination. This approach demonstrated acceptable accuracy for assaying d-carnitine in complex matrices such as drug preparation and milk. This work pioneers the combination of a polysaccharide hydrogel as a chiral selector with a nanozyme as the CL indicator for the effective discrimination of enantiomers, offering an innovative tool for the development and production of chiral drugs.
由于对映体的物理化学性质差异极小，不依赖色谱技术进行简便的手性识别长期以来一直是一项巨大挑战。具有天然手性选择性的多糖水凝胶有望成为构建手性识别平台的材料。在本研究中，制备了 l-半胱氨酸诱导的钴纳米簇（LC-CoNCs）并将其用作手性纳米酶，以增强鲁米诺-H₂O₂体系的化学发光（CL）信号。基于 LC-CoNCs 与肉碱对映体在 Ca²⁺交联海藻酸钠（SA）水凝胶界面上的竞争亲和力，建立了一种用于有效区分肉碱对映体的 CL 方法。采用该策略，d-肉碱导致 CL 信号显著抑制，而 l-肉碱对 CL 信号未表现出抑制作用。根据密度泛函理论计算和接触角测量结果，由于 SA 和 Ca²⁺的协同作用，水凝胶显示出 d-肉碱>LC-CoNCs>l-肉碱的亲和力顺序，这是实现有效区分的基础。该方法在测定药物制剂和牛奶等复杂基质中的 d-肉碱时显示出可接受的准确性。这项工作开创了将多糖水凝胶作为手性选择剂与纳米酶作为 CL 指示剂相结合的方法，用于有效区分对映体，为手性药物的开发和生产提供了一种创新工具。
