Key Laboratory of Functional Polymer Materials, Ministry of Education, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), and College of Chemistry, Nankai University , Tianjin 300071, P. R. China.
Biomacromolecules. 2014 May 12;15(5):1663-75. doi: 10.1021/bm500086e. Epub 2014 Apr 4.
A facile and highly efficient new approach (namely RAFT coupling chemistry) to obtain well-defined hydrophilic molecularly imprinted polymer (MIP) microspheres with excellent specific recognition ability toward small organic analytes in the real, undiluted biological samples is described. It involves the first synthesis of "living" MIP microspheres with surface-bound vinyl and dithioester groups via RAFT precipitation polymerization (RAFTPP) and their subsequent grafting of hydrophilic polymer brushes by the simple coupling reaction of hydrophilic macro-RAFT agents (i.e., hydrophilic polymers with a dithioester end group) with vinyl groups on the "living" MIP particles in the presence of a free radical initiator. The successful grafting of hydrophilic polymer brushes onto the obtained MIP particles was confirmed by SEM, FT-IR, static contact angle and water dispersion studies, elemental analyses, and template binding experiments. Well-defined MIP particles with densely grafted hydrophilic polymer brushes (∼1.8 chains/nm(2)) of desired chemical structures and molecular weights were readily obtained, which showed significantly improved surface hydrophilicity and could thus function properly in real biological media. The origin of the high grafting densities of the polymer brushes was clarified and the general applicability of the strategy was demonstrated. In particular, the well-defined characteristics of the resulting hydrophilic MIP particles allowed the first systematic study on the effects of various structural parameters of the grafted hydrophilic polymer brushes on their water-compatibility, which is of great importance for rationally designing more advanced real biological sample-compatible MIPs.
描述了一种简便、高效的新方法（即 RAFT 偶联化学），用于获得对实际未稀释生物样品中的小分子有机分析物具有出色特异性识别能力的定义明确的亲水性分子印迹聚合物（MIP）微球。它涉及通过 RAFT 沉淀聚合（RAFTPP）首次合成具有表面结合的乙烯基和二硫酯基团的“活”MIP 微球，然后通过简单的偶联反应将亲水性大分子 RAFT 试剂（即具有二硫酯端基的亲水性聚合物）与“活”MIP 颗粒上的乙烯基接枝到亲水性聚合物刷上。在自由基引发剂存在下。通过 SEM、FT-IR、静态接触角和水分散研究、元素分析和模板结合实验证实了成功地将亲水性聚合物刷接枝到获得的 MIP 颗粒上。很容易获得具有所需化学结构和分子量的紧密接枝亲水性聚合物刷的定义明确的 MIP 颗粒（∼1.8 链/nm(2))，其表面亲水性显著提高，因此可以在实际生物介质中正常工作。阐明了聚合物刷高接枝密度的起源，并证明了该策略的通用性。特别是，所得亲水性 MIP 颗粒的明确特征允许首次对接枝亲水性聚合物刷的各种结构参数对其水相容性的影响进行系统研究，这对于合理设计更先进的实际生物样品兼容 MIP 非常重要。
