Guo Dandan, Zheng Diya, Zhou Ding, Tong Changlun, Huang Shaohua
Institute of Drug Discovery Technology, Ningbo University, Ningbo, 315211, China.
Institute of Drug Discovery Technology, Ningbo University, Ningbo, 315211, China.
Talanta. 2025 Jan 1;282:126972. doi: 10.1016/j.talanta.2024.126972. Epub 2024 Sep 27.
Lysine (Lys) is an essential nutrient that plays a crucial role in the growth and development of living organisms. Chiral analysis of Lys holds significant importance for ensuring the safety of food, pharmaceuticals, and health products. In this work, an achiral Zr-based metal organic frameworks (MOFs), UiO-66-NH, was proposed as a fluorescent probe to achieve rapid response to l-lysine (L-Lys) in solution. Additionally, Zr in the skeleton of UiO-66-NH framework exhibited different binding capacities towards Lys enantiomers, leading to distinct fluorescence responses for L-Lys and d-lysine (D-Lys). Leveraging these properties, the UiO-66-NH probe enabled accurate determination of L-Lys concentrations in solution, as well as the enantiomeric excess (ee) values of Lys solutions. Notably, in the detection of Lys enantiomers, the achiral UiO-66-NH acted as both a chiral selector and a fluorescent indicator, greatly improving the efficiency and stability of the detection system. The probable mechanism was further elucidated by pH titration experiments and density functional theory calculations. Additionally, the general applicability of this mechanism was validated by similar amino MOFs. The application of the UiO-66-NH fluorescent probe in analysis of infant formula milk powders and liquid milk samples confirmed the reliability of the method. Moreover, the construction of fluorescence test paper by immobilizing UiO-66-NH onto filler papers enabled the rapid identification of Lys enantiomers. Compared to previous fluorescent analyses of chiral amino acids assisted by additional metal ions, this study presented a novel approach and methodology that offers high efficiency, stability, reproducibility and reusability for the identification and detection of Lys enantiomers, highlighting the potential of the UiO-66-NH fluorescent probe in advancing analytical techniques.
赖氨酸（Lys）是一种必需营养素，在生物的生长和发育中起着至关重要的作用。赖氨酸的手性分析对于确保食品、药品和保健品的安全具有重要意义。在这项工作中，一种非手性的锆基金属有机框架（MOF），UiO-66-NH，被提议作为一种荧光探针，以实现对溶液中L-赖氨酸（L-Lys）的快速响应。此外，UiO-66-NH框架骨架中的锆对赖氨酸对映体表现出不同的结合能力，导致对L-Lys和D-赖氨酸（D-Lys）有明显不同的荧光响应。利用这些特性，UiO-66-NH探针能够准确测定溶液中L-Lys的浓度以及赖氨酸溶液的对映体过量（ee）值。值得注意的是，在检测赖氨酸对映体时，非手性的UiO-66-NH既作为手性选择剂又作为荧光指示剂，大大提高了检测系统的效率和稳定性。通过pH滴定实验和密度泛函理论计算进一步阐明了可能的机理。此外，类似的氨基MOF验证了该机理的普遍适用性。UiO-66-NH荧光探针在婴儿配方奶粉和液态奶样品分析中的应用证实了该方法的可靠性。此外，通过将UiO-66-NH固定在填充纸上构建荧光试纸，能够快速识别赖氨酸对映体。与先前借助额外金属离子辅助的手性氨基酸荧光分析相比，本研究提出了一种新颖的方法和技术，为赖氨酸对映体的识别和检测提供了高效、稳定、可重复和可重复使用的特性，突出了UiO-66-NH荧光探针在推进分析技术方面的潜力。
