点击反应制备分级孔金属-有机框架材料整体柱及其在富集和电色谱分离中的应用

Metal-organic frameworks (MOF) have been widely applied in fields such as chromatographic separation and sample pretreatment due to unique properties such as diverse structure topology, high surface area and tunable pore size. However, due to the natural microporous structure of MOF, MOF-based stationary phases are confronted by issues such as low separation efficiencies and tremendous challenges in separating high-molecular-weight compounds. In this project, we have targeted these key issues through the controlled design and synthesis of mesoporous-microporous hierarchical porous MOF (HP-MOF) stationary phase that show a high level of chemical stability and modifiable pore characteristics, thus showing improved high-molecular-weight analytes’ retention and mass transfer process. The controllable synthesis of mesoporous structure in microporous MOF with high stability and tailorable pore characters was successfully realized based on a versatile modulator-induced defect-formation strategy. Polymerizable vinyl functional HP-MOF monomers were first synthesized via post-synthesis modification, followed by the introduction of polythiol cross-linking agents, to enable the preparation of HP-MOF monoliths in a one-pot synthesis based on thiol-ene click chemistry. We then established a novel combinatorial method for in-tube solid phase microextraction– capillary electrochromatography based on HP-MOF monoliths, which focuses on two crucial analytical procedures: sample pretreatment and chromatographic separation. This method was then used for the highly efficient enrichment, and effective separation and detection of glycopeptide antibiotic residues in complex food samples, which provides an effective tool for food safety monitoring and food safety assessment.

金属-有机框架材料(MOF)具有组成和结构丰富、比表面积大及孔径可调控等特点，已在色谱分离和样品预处理等领域得到了广泛应用。然而由于MOF天然微孔结构特性，目前MOF固定相存在着分离效率低及分离大分子化合物面临巨大挑战的问题。本项目针对这些关键问题，可控设计合成化学稳定性高，孔特征可剪裁的介孔-微孔分级多孔MOF（HP-MOF）色谱填料，增加大分子分析物的色谱保留及提高传质速度。基于简单有效的调节剂诱导缺陷形成方法，在MOF内部可控地构造规则的介孔结构。拟采用后合成修饰策略，设计合成可聚合的乙烯基化HP-MOF单体，引入多巯基交联剂，基于巯基－烯点击化学制备HP-MOF整体柱。在此基础上，围绕样品预处理与色谱分离两个分析过程，构建基于HP-MOF整体柱的管内固相微萃取－电色谱联用新方法，应用于复杂食品样品中糖肽类抗生素残留的高效富集及有效的分离检测，为食品安全监控和安全性评价提供有力手段。

金属-有机/共价-有机框架材料 (MOF/COF)具有组成和结构丰富、比表面积大、孔径可调控等特点，已在分离分析等领域得到了广泛应用。然而由于MOF/COF天然微孔结构特性，目前MOF/COF用于样品前处理存在着传质效率低及吸附大分子化合物面临巨大挑战的问题。针对上述关键科学问题，本项目可控设计合成一系列分级孔MOF/COF材料，增强其分离富集性能及拓宽其应用范围。通过本项目的资助，取得了以下研究成果：(1)发展了高效制备分级孔及表面功能化MOF/COF材料的新策略，研究了其吸附机理，建立了基于MOF/COF吸附剂的复杂基体样品中糖肽类抗生素、四环素、全氟酸类物质、洛芬类药物、阳离子染料等的样品前处理新方法，实现了分析物的高效富集及其与基体的有效分离。(2)合成集成MALDI基质和特异性富集功能的两种多孔COF材料，分别用于MALDI-TOF MS直接分析顺二醇类小分子、季胺类农药；设计研制了磁性介孔金属-酚醛配位球并用于萃取鱼肉中的结晶紫及其代谢物。(3) 设计合成了一种非金属氢键-有机框架(HOF)催化剂，将其涂层到玻璃纤维滤膜上得到HOF复合材料，并填塞到注射器中制成催化柱，用于高效催化降解环境污染物4-硝基酚。(4)此外，本项目基于MOF/COF开放的金属位点及光催化等优点，同时进行了相关拓展研究。研制了一系列多功能MOF纳米酶，构建基于纳米酶的光学传感系统，并应用于生物活性小分子的检测；开发了具有光催化活性的多功能MOF/COF材料，用于细菌的灵敏检测与高效杀灭。本项目有关研究成果已在Analytical Chemistry, ACS Applied Materials & Interfaces, Chemical Communications, Journal of Chromatography A, Analyst, Talanta等SCI源刊物上发表论文22篇。研究结果对于多孔MOF/COF材料的合成及拓宽其在分析化学领域的应用具有十分重要的指导意义。