磁性磷光印迹材料用于微囊藻毒素的富集、检测与降解

In this project, we focus on the molecular recognition and elimination of microcystins, taking advantages of nanotechnology, surface functional design, molecular imprinting technology, phosphorescence detection and magnetic separation and enrichment technology to develop microcystins imprinting nanomaterials that has high ratio of imprinting sites, good selectivity and affinity, and fast binding kinetics. Because of the large specific area of molecular imprinting nanomaterials, the majority binding sites are located on or near their surface, so it is conceivable that the difficulties of traditional molecular imprinting can be overcome. Moreover, we use magnetic particles and phosphorescent quantum dots to form layer-by-layer self-assemble molecular imprinting materials. Therefore, our materials possess both functions of magnetic separation and phosphorescent detection when the molecular imprinting nanomaterial was used for recognizing and eliminating the targets of microcystins. When used for detection, the molecular imprinting nanomaterial can prevent the interference from the scattered light and the fluorescence background of water samples. The recognition mechanisms for microcystins were clarified. The investigation will not only offer the new method for the synthesis of imprinting nanomaterials, but also provide promising means for phosorescence detection of other target molecules.

本项目将重点针对藻毒素的分子识别与清除，结合磁性纳米颗粒分离、催化性能以及量子点的磷光检测功能，发展制备高密度印迹位点、高选择性、高亲和力和快速结合动力学的藻毒素印迹纳米材料。由于纳米分子印迹材料具有较高的比表面积，结合位点大多位于或接近材料表面，因此有望真正解决传统分子印迹材料用于富集检测时遇到的困难。本项目将磁性纳米颗粒和磷光量子点颗粒通过层层自主装的方式形成分子印迹材料，使得材料对目标物微囊藻毒素同时具有磁性分离富集功能、磷光检测功能以及催化清除功能。本项目亦将探索合成的分子印迹材料对微囊藻毒素的识别特性和敏感机制，为将该检测平台能实际用于其它环境目标物的检测提供研究思路和理论依据。

微囊藻毒素（Microcystins，MCs）是蓝藻水华的次生代谢产物，具有较强的毒性，化学性质稳定难以降解，开发新的微囊藻毒素检测方法对于环境质量监测和公共健康安全等都具有十分重要的意义。量子点（Quantum Dots, QDs）与分子印迹聚合物（Molecular Imprinting Polymers, MIPs）相结合为MCs的光学识别分析开启了全新的解决方案。室温磷光（Room-temperature phosphorescence, RTP）相对于荧光分析具有良好的抗干扰能力，选择性进一步的提高。本项目以磷光量子点为研究基础，开发了不同的室温磷光量子点，并且与MIPs技术联用进行微囊藻毒素的检测，同时进一步拓展了室温磷光量子的应用。项目完成的主要内容如下：.1.ZnSe:Mn/ZnS QDs和单克隆微囊藻毒素-LR（抗MC-LR）抗体通过EDC/NHS形成偶联生物共轭体作为RTP探针用于检测MC-LR。优化的条件下，生物共轭体MC-LR的线性范围为0.9-8.8 nM。检测限为0.038 nM。本实验方法应用于环境水样的检测与高效液相色谱的检测结果一致。.2.通过结合Mn:ZnS QDs的RTP性质和双虚拟片段MIPs技术，构建了一种新型的RTP探针用于MCs的检测。以目标分析物MCs的片段或结构相似的L-精氨酸和戊基苯作为双虚拟片段分子模板，形成的识别位点检测一系列的MCs。这种方法无需任何衍生化和诱导剂。在优化条件下, 双虚拟片段磷光量子点印迹材料检测MC-LR的线性范围0.0025-0.165 nM，最低检测浓度为0.0025 nM。同时对长江、湖水中的MC-LR进行了检测，证明了本方法的实用性。.3.设计了一种纤维素保护的氮化碳QDs室温磷光膜材料用于三聚氰胺的可视化智能检测。膜材料的RTP发射峰在波长510 nm - 590 nm范围内随着激发波长的变化而改变，RTP寿命43 ms，余辉时间持续5 s。我们基于膜材料开发手机图像识别检测三聚氰胺的线性范围在0.18-2.07 mg/kg，检出限为0.018 mg/kg， 并且将该方法用于牛奶商品的实际检测，取得了满意的效果。