Tang Yu-Hong, Ma Tian-Tian, Ran Xu-Qin, Yang Yukun, Qian Hai-Long, Yan Xiu-Ping
Institute of Analytical Food Safety, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
School of Life Science, Shanxi University, Taiyuan 030006, China.
J Hazard Mater. 2024 Jul 5;472:134469. doi: 10.1016/j.jhazmat.2024.134469. Epub 2024 Apr 28.
The scarcity of selective adsorbents for efficient extraction and removal of microcystins (MCs) from complex samples greatly limits the precise detection and effective control of MCs. Three-dimensional covalent organic frameworks (3D COFs), characterized by their large specific surface areas and highly ordered rigid structure, are promising candidates, but suffer from lack of specific recognition. Herein, we design to engineer molecularly imprinted cavities within 3D COFs via molecularly imprinted technology, creating a novel adsorbent with exceptional selectivity, kinetics and capacity for the efficient extraction and removal of MCs. As proof-of-concept, a new CC bond-containing 3D COF, designated JNU-7, is designed and prepared for copolymerization with methacrylic acid, the pseudo template L-arginine and ethylene dimethacrylate to yield the JNU-7 based molecularly imprinted polymer (JNU-7-MIP). The JNU-7-MIP exhibits a great adsorption capacity (156 mg g) for L-arginine. Subsequently, the JNU-7-MIP based solid-phase extraction coupled with high performance liquid chromatography-mass spectrometry achieves low detection limit of 0.008 ng mL, wide linear range of 0.025-100 ng mL, high enrichment factor of 186, rapid extraction of 10 min, and good recoveries of 92.4%-106.5% for MC-LR. Moreover, the JNU-7-MIP can rapidly remove the MC-LR from 1 mg L to levels (0.26-0.35 μg L) lower than the WHO recommended limit for drinking water (1 μg L). This work reveals the considerable potential of 3D COF based MIPs as promising adsorbents for the extraction and removal of contaminants in complex real samples.
用于从复杂样品中高效提取和去除微囊藻毒素（MCs）的选择性吸附剂的稀缺，极大地限制了对MCs的精确检测和有效控制。三维共价有机框架（3D COFs）具有大比表面积和高度有序的刚性结构，是很有前景的候选材料，但缺乏特异性识别能力。在此，我们设计通过分子印迹技术在3D COFs中构建分子印迹空腔，制备出一种对MCs具有优异选择性、动力学性能和吸附容量的新型吸附剂，用于高效提取和去除MCs。作为概念验证，设计并制备了一种含CC键的新型3D COF，命名为JNU-7，将其与甲基丙烯酸、伪模板L-精氨酸和二甲基丙烯酸乙二醇酯共聚，得到基于JNU-7的分子印迹聚合物（JNU-7-MIP）。JNU-7-MIP对L-精氨酸表现出很大的吸附容量（156 mg/g）。随后，基于JNU-7-MIP的固相萃取结合高效液相色谱-质谱联用，实现了0.008 ng/mL的低检测限、0.025 - 100 ng/mL的宽线性范围、186的高富集倍数、10分钟的快速萃取以及对MC-LR 92.4% - 106.5%的良好回收率。此外，JNU-7-MIP能迅速将1 mg/L的MC-LR去除至低于世界卫生组织饮用水推荐限值（1 μg/L）的水平（0.26 - 0.35 μg/L）。这项工作揭示了基于3D COF的MIPs作为从复杂实际样品中提取和去除污染物的有前景吸附剂的巨大潜力。
