柱芳烃基水溶性共轭聚合物荧光探针对有机小分子的高效检测及其构效关系研究

The residue of water soluble small organic molecules even at trace levels not only seriously cause water contamination, but also severely impair the ecosystem, posing a great danger to people's daily life. Generally, the detection of small organic molecules have been performed using conventional chromatographic techniques. Although these techniques offer powerful trace analysis with excellent sensitivity and high reproducibility, many drawbacks, such as sophisticated equipment, time consuming, tedious sample preparation and purification steps, obviously limited their on-site and real-time application, particularly emergency cases. Therefore, the analysis of water-soluble small organic molecules is an urgent demand to ensure water safety, safeguard the ecosystem and protect human health from possible hazards. The most common polymeric materials or families employed as sensors is widely exploited in the detection of heavy metallic cations and anionic species. In this project, the rational functionalization of pillar[n]arenes (n=5, 6) could yield specific recognition groups and rigid building units that could be used to construct water soluble conjugated polymers fluorescent probe for detection of small organic molecules based on covalently-linked pillararenes. The main research content is as follows: electronegativity of substituents in pillararene and steric effect were investigated for its complexation ability and selectivity based on host-guest interactions; the complexation ability and selectivity of water-soluble conjugated polymers containing pillararene groups in the main or side chains was studied; fluorescence properties of conjugated polymers obtained by changing the monomer were investigated to realize the fluorescence detection of small organic molecules. The research will provide new building materials for detection of small organic molecules with high sensitivity and selectivity.

水体中微量水溶性有机小分子污染物的快捷、原位检测技术面临巨大挑战。目前的聚合物基探针大多针对重金属离子和无机阴离子等的检测。本项目拟以大环结构柱[5]芳烃或柱[6]芳烃单元为识别基团和构筑单元，通过共价键将其连接到水溶性共轭聚合物中，构建柱芳烃基水溶性共轭聚合物荧光探针，实现对水体中微量水溶性有机小分子的高效检测。主要研究内容如下：基于主客体化学作用，通过调控柱芳烃两端修饰基团的电负性和空间位阻优化柱芳烃单元对客体的络合能力和选择性；研究柱芳烃单元分别位于聚合物主链或侧链时调控其对客体分子的络合能力；研究改变共聚单体结构调控所得聚合物的荧光性能，实现对水溶性有机小分子的快速检测。其创新性体现在构筑了识别基团为柱芳烃结构的水溶性共轭聚合物，实现对水溶性有机小分子的快捷检测。本项目为实现对有机物的特异性检测提供了新型物质结构。

水体中微量有机小分子污染物的快捷、原位检测技术面临巨大挑战。本课题以大环结构柱[5]芳烃单元为识别基团和构筑单元，通过共价键将其连接到共轭聚合物中，构建柱芳烃基共轭聚合物荧光探针，研究其对客体分子的络合能力。（1）以柱[5]芳烃单体M-1和四苯乙烯单元共聚得到新型共聚物Co-P[5]TPE，研究表明，Co-P[5]TPE在二甲基亚砜(DMSO)和水的混合物中表现出聚集诱导发射增强(AIEE)效应。在DMSO/H2O溶液(VDMSO/Vwater=7/3)中，低聚物对百草枯(PQ)的荧光响应优于其他竞争客体。通过荧光滴定实验计算得到的Stern-Volmer常数(KSV)为2.144×104 M-1，LOD为1.54×10-8 M，该聚合物是一种对PQ具有高选择性、灵敏度和抗干扰性能的聚合物荧光探针。通过透射电镜(TEM)、动态光散射(DLS)和前沿轨道(HOMO和LUMO)、静电势(ESP)和非共价相互作用(NCI)等理论计算研究了可能的识别机制。.（2）以柱[5]芳烃单体M-1和芴单元共聚得到新型共聚物Co-P[5]Flu，研究表明，Co-P[5]Flu在乙醇和水的混合物中对百草枯(PQ)的荧光响应(1-I/I0=96.6%)优于其他竞争客体。通过荧光滴定实验计算得到的Stern-Volmer常数(KSV)为2.117×104 M-1，LOD为1.69×10-8 M，该聚合物是一种对PQ具有高选择性、灵敏度和抗干扰性能的聚合物荧光探针。.本项目的创新性体现在构筑了识别基团为柱芳烃结构的共轭聚合物，实现对甲基紫晶的快捷检测。通过实验和理论计算提出了柱芳烃结构与甲基紫晶间可能的作用机理。本项目的研究为实现对有机物的特异性检测提供了新型物质结构。