Zheng Chen-Yan, Li Hao-Ze, Qian Hai-Long, Yang Cheng, Yan Xiu-Ping
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China.
Anal Chem. 2025 Jul 8;97(26):14067-14075. doi: 10.1021/acs.analchem.5c02824. Epub 2025 Jun 24.
Chiral covalent-organic framework (COF) nanochannel membranes with ordered channels and predesigned structures play a pivotal role in enantioselective sensing. However, the enantioselectivity of chiral COFs is still limited due to the lack of chiral environment regulating. Herein, we report a self-standing chiral copper-coordinated COF (COF-Cu(II)) nanochannel membrane for the enantioselective sensing of reducing amino acids based on the synergistic integration of stereochemical recognition and redox-responsive signal amplification. With phenylethylamine as a chiral catalyst, a tris(-salicylideneamine)-derived β-ketoenamine-COF was prepared via the interfacial polymerization asymmetric catalysis of 1,3,5-triformylphloroglucinol (TP) and 4,4',4″-triaminotriphenylamine (TAPA). Furthermore, the Cu(II)-coordinated chiral COF (chiral COF-Cu(II), (Δ)- and (Λ)-COF-Cu(II)) nanochannel membranes were obtained via postmodification. The chiral COF structure creates spatially confined cavities for stereochemical recognition, while the Cu(II) acts as a redox-responsive switch. Selective binding to reducing amino acid enantiomers resulted in the reduction of the coordinated Cu(II) in COF nanochannel membranes to Cu(I), affecting the wettability and surface charge density for transmembrane ion transport to achieve enantioselective sensing. The as-prepared chiral sensor exhibited excellent enantioselective sensing performance for reducing amino acids such as l/d-cysteine, l/d-arginine, and l/d-proline (limits of detection of 13 - 21 pg L). This study shows the tremendous potential of a chiral metal-coordinated COF nanochannel membrane for enantioselective sensing.
具有有序通道和预先设计结构的手性共价有机框架（COF）纳米通道膜在对映选择性传感中起着关键作用。然而，由于缺乏手性环境调节，手性COF的对映选择性仍然有限。在此，我们报道了一种自支撑的手性铜配位COF（COF-Cu(II)）纳米通道膜，基于立体化学识别和氧化还原响应信号放大的协同整合，用于还原型氨基酸的对映选择性传感。以苯乙胺为手性催化剂，通过1,3,5-三(甲酰基)间苯三酚（TP）和4,4',4''-三氨基三苯胺（TAPA）的界面聚合不对称催化制备了一种三（水杨醛亚胺）衍生的β-酮烯胺-COF。此外，通过后修饰获得了Cu(II)配位的手性COF（手性COF-Cu(II)，(Δ)-和(Λ)-COF-Cu(II)）纳米通道膜。手性COF结构为立体化学识别创造了空间受限的空腔，而Cu(II)充当氧化还原响应开关。对还原型氨基酸对映体的选择性结合导致COF纳米通道膜中配位的Cu(II)还原为Cu(I)，影响跨膜离子传输的润湿性和表面电荷密度，以实现对映选择性传感。所制备的手性传感器对l/d-半胱氨酸、l/d-精氨酸和l/d-脯氨酸等还原型氨基酸表现出优异的对映选择性传感性能（检测限为13 - 21 pg L）。这项研究展示了手性金属配位COF纳米通道膜在对映选择性传感方面的巨大潜力。
