Guo Hongying, Li Yang, Li Yijun, He Xiwen, Chen Langxing, Zhang Yukui
College of Chemistry, Tianjin Key Laboratory of Biosensing and Molecular Recognition, Nankai University, Tianjin 300071, China.
School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University, Tianjin 300350, China.
ACS Appl Mater Interfaces. 2023 Mar 22;15(11):14777-14787. doi: 10.1021/acsami.2c22386. Epub 2023 Mar 10.
Covalent organic frameworks (COFs) have attracted impressive interest in separation on aqueous media. Herein, we integrated the stable vinylene-linked COFs with magnetic nanosphere via the monomer-mediated in situ growth strategy to construct a crystalline FeO@v-COF composite for enrichment and determination of benzimidazole fungicides (BZDs) from complex sample matrices. The FeO@v-COF has a crystalline assembly, high surface area, porous character together with a well-defined core-shell structure, and serves as progressive pretreatment materials for magnetic solid phase extraction (MSPE) of BZDs. Adsorption mechanism studies revealed that the extended conjugated system and numerous polar cyan groups on v-COF provides abundant π-π and multiple hydrogen bonding sites, which are conducive to interact with BZDs collaboratively. FeO@v-COF also displayed enrichment effects to various polar pollutions with conjugated structures and hydrogen-bonding sites. FeO@v-COF-based MSPE-high-performance liquid chromatography exhibited the low limit of detection, wide linearity, and good precision. Moreover, FeO@v-COF showed better stability, enhanced extraction performance, and more sustainable reusability in comparison with its imine-linked counterpart. This work proposes a feasible strategy on constructing the crystalline stable magnetic vinylene-linked COF composite for the determination of trace contaminants in complex food matrices.
共价有机框架材料（COFs）在水相介质分离方面引起了广泛关注。在此，我们通过单体介导的原位生长策略将稳定的亚乙烯基连接的COFs与磁性纳米球整合，构建了一种结晶性的FeO@v-COF复合材料，用于从复杂样品基质中富集和测定苯并咪唑类杀菌剂（BZDs）。FeO@v-COF具有结晶组装结构、高比表面积、多孔特性以及明确的核壳结构，可作为BZDs磁性固相萃取（MSPE）的先进预处理材料。吸附机理研究表明，v-COF上扩展的共轭体系和众多极性氰基提供了丰富的π-π和多重氢键位点，有利于与BZDs协同相互作用。FeO@v-COF对具有共轭结构和氢键位点的各种极性污染物也表现出富集效果。基于FeO@v-COF的MSPE-高效液相色谱法具有低检测限、宽线性范围和良好的精密度。此外，与亚胺连接的同类材料相比，FeO@v-COF表现出更好的稳定性、增强的萃取性能和更可持续的可重复使用性。这项工作为构建用于测定复杂食品基质中痕量污染物的结晶稳定磁性亚乙烯基连接的COF复合材料提出了一种可行策略。
