基于多巴胺及其衍生物的新型磁性纳米固相萃取剂的制备及其在环境分析中的应用

According to the original plans of the Young Scientist Fund (No. 20907061), different kind of magnetic nanomaterials adsorbents were synthesized successfully including those modified with octadecyl (C18) and aminopropyl mixed groups, coated with alginate biopolymers or phosphatidylcholine bilayer and encapsulated with surface-tunable carbon. These adsorbents not only possessed large specific surface areas and strong adsorption trends to pollutants, but also could selectively preconcentrate certain kind of organic pollutants and showed excellent anti-interference ability to environmental matrixes. This project has provided a novel concept to efficiently and quickly enrich organic pollutants from environmental samples with complex matrixes. Several research papers about this research have been published in famous journals including Anal Chem, J Chromatogr A, and Anal Chim Acta and two patents have been authorized. The new project continuously focuses on the preparation of novel nanomaterials and their application in sample pretreatment. We propose a new efficient, “green”, convenient, and controllable technique to synthesize solid-phase extraction (SPE) adsorbents based on dopamine or its derivatives and nanoscaled Fe3O4 taking advantage of the special properties of dopamine such as auto-polymerization, adhesion, redox, and easy to modify. The SPE adsorbents with various functional groups of general type or selected type can be prepared with this new technique. The new project is an original scientific research work combined nanomaterials, biomimetic modification and magnetic SPE techniques.

按照原青年基金项目的目标，成功制备了C18和氨丙基混合官能团修饰的磁性纳米吸附剂，海藻酸聚合物或磷脂双分子包覆的及表面性质可调控的碳材料包覆的磁性纳米吸附剂。该类吸附剂既具有纳米材料的高比表面积和强吸附性能，又对特定类型有机污染物具有选择性富集能力，还表现出优良的抗环境介质干扰能力。该研究为复杂基体环境样品中有机污染物高效、快速富集提供了一种新思路，课题研究结果已在Anal Chem，J Chromatogr A和Anal Chim Acta等期刊上发表论文7篇，并获两项授权专利。本研究项目将继续新型纳米材料的制备及在环境样品前处理中的应用研究，拟以多巴胺及其衍生物和纳米Fe3O4为基质，利用多巴胺的自聚合、粘附、氧化还原和易于修饰的特性，高效、绿色、方便、可控地制备官能团种类丰富的通用型或选择型的新型磁性纳米固相萃取剂。本项目是将纳米材料、仿生修饰和磁性固相萃取等结合为一体的创新性研究。

经过四年的研究，基于多巴胺和多酚类物质，制备了8种新型复合纳米材料吸附剂及催化剂。根据多巴胺自聚合的性质，将聚多巴胺包覆在磁性纳米Fe3O4表面，得到核壳式聚多巴胺包覆的磁性纳米材料（Fe3O4@PDA），该材料既对有机污染物具有富集能力，又可作为MALDI基质直接用TOF-MS对所富集的有机污染物进行快速检测。以聚多巴胺包覆的磁性纳米材料为吸附剂和MALDI基质，建立了磁性固相萃取和MALDI-TOF MS相结合一体化分析检测有机污染物的技术。基于多巴胺包覆的磁性Fe3O4颗粒，利用多巴胺粘合和还原的性质，通过室温搅拌等温和方法制备了新型石墨烯磁性复合材料和负载纳米金颗粒的复合磁性材料，该类材料对硝基苯、亚甲基蓝染色剂等有机污染物具有高效的催化降解及吸附去除能力。以自然界广泛存在的廉价的天然物质聚多酚（包括单宁酸、没食子酸、儿茶素）为还原剂和螯合剂制备了聚多酚-金属离子超分子聚合物包覆的纳米金，可催化还原硝基酚等污染物。以多酚类化合物没食子酸为有机配体，合成了多种具有分级有序结构的金属-没食子酸纳米材料，并将其碳化，制备成了负载金属纳米颗粒的复合纳米材料，以该材料为吸附剂或催化剂，可以高效去除水溶液中的氯酚和硝基苯等污染物。这些实验结果表明以自然界中含量丰富的天然物质多巴胺及多酚类物质为原材料，可以简单、绿色、可控、高效制备复合纳米吸附剂及催化剂；所制备的材料稳定性好，且对环境中有机污染物具有较强的富集、吸附或降解去除能力。总之，本研究提供了一种简单、快速、便利、全新地制备固相萃取剂、吸附剂或催化剂的方法。这些研究成果发表论文19篇，其中SCI论文17篇，影响因子大于5的7篇，申请发明专利2个。