分子瓶刷功能化磁性石墨烯基超高容量、超高选择性吸附剂的可控制备及其应用

Adsorbents with high capacity and high selectivity is the key for enrichment and purification of target molecules from complex samples, their design and preparation is the key issue in separation science. The present project, which is proposed on the basis of our preliminary work, utilize the superiority that surface-initiated atom transfer radical polymerization (SI-ATRP) is capable of grafting high density polymer chains onto solid surfaces, exploit the principle that multivalent ligand can provide superselectivity, and take advantage of super high specific surface area of graphene. Taking boronate affinity, immobilized metal ion affinity, reversed phase and ion exchange adsorbents as examples, molecular bottlebrush which contains very high density ligands and has mimetic structure to a kind of natural multivalent ligands will be innovatively grafted onto polydopamine coated magnetic graphene to prepare adsorbents with supercapacity and super selectivity. The adsorption properties of proteins and small molecules, multivalent molecules and monovalent molecules on the new adsorbents will be investigated, the relationships between the selectivity or adsorption capacity and molecular bottlebrush structure on the surface of the materials will be elucidated, the role of multivalent interaction played in elevating the selectivity of the adsorbents will be revealed. A new idea for design and preparation of high capacity and high selectivity adsorbents will be provided. Taking small molecules and proteins in biological and environmental samples for examples, the superiority of the new adsorbents in isolation, enrichment and purification of target molecules from complex samples will be clarified.

高容量、高选择性吸附剂是复杂样品中目标物高效分离富集和纯化的关键，其设计和制备是分离科学研究中长期探索的关键科学问题。在前期工作基础上，本项目利用表面引发-原子转移自由基聚合（SI-ATRP）可在材料表面高密度接枝聚合物链的优势和多价配体可提供超高选择性的原理，并结合石墨烯具有超高比表面积的特点，以硼酸亲和、固定化金属离子亲和、反相和离子交换吸附剂为例，创新性地将配体密度极高、且具有仿天然多价配体结构的分子瓶刷高密度地接枝在聚多巴胺包覆磁性石墨烯表面，建立制备超高容量、超高选择性吸附剂的方法；考察新型吸附剂对蛋白质和有机小分子、多价分子和单价分子的吸附性能，阐明吸附容量和选择性与分子瓶刷结构之间的关系，阐述多价作用对提高吸附剂选择性的贡献，为高容量、高选择性吸附剂的结构设计和制备提供新思路；以生物和环境样品中的小分子和蛋白质为例，阐明新型吸附剂在复杂样品分离富集和纯化中的优势。

本项目针对如何高效制备高容量和高选择性吸附剂的关键科学问题，采用原子转移自由基聚合，将具有不同拓扑结构和组成的高分子聚合物刷接枝在聚多巴胺包覆磁性石墨烯或磁性纳米粒子表面，制备了硼酸亲和、固定化金属离子亲和、反相和离子交换等多种高容量、高选择性吸附剂，考察了各种吸附剂的吸附性能，并用于实际样品中痕量分析物的分离富集和纯化。结果表明分子瓶刷聚合物在提高吸附剂的吸附容量和选择性方面具有很大的应用潜力，其固有的特殊拓扑结构和可提供多价作用的优点赋予了吸附剂特殊的选择性和对分析物的强亲和力。此外，还制备了几种新型的磁性碳吸附剂和功能化磁性共价有机聚合物吸附剂，这些吸附剂均表现出良好的吸附性能。这些吸附剂应用于痕量样品富集时，具有选择性高、吸附剂用量少、富集能力强等优点，提高了富集效率和分析方法的灵敏度，在生物分析、环境分析以及蛋白质分离纯化等复杂样品分离分析领域具有一定的应用潜力，同时该项目研究结果对固体催化、药物运输、传感分析等与分子识别相关的其他领域也具有重要意义。