基于分子印迹技术的非II-VI族量子点比率荧光探针的构建及其在环境激素可视化检测中的研究

Environmental hormones are widely dispersed in the environment. Even if the environmental hormones are in low level, it can cause great harm to humans, animals and ecological environment. At present, environmental hormones are detected mostly by chromatographic technology. Although these methods possess high sensitivity and excellent selectivity, the instruments used are expensive and sample pretreatments are relatively complicated. Therefore, there is still an increasing need to develop simple and sensitive novel methods for the determination of environmental hormone. Ratiometric fluorescence strategy has become a powerful tool for the detection of trace amounts of analyte because of its simplicity, sensitivity and cost-effective instrumentation. More importantly, the ratiometric sensors can provide a reference signal, so we can easily observe the change of the fluorescence colours and facilitate the visual identification. To the best of our knowledge, the ratiometric fluorescence probe based on quantum dots for the detection of environmental hormones has not been reported yet. Compared with cadmium-containing quantum dots and fluorescent organic dyes, non-group II-VI quantum dots have unique optical properties and excellent biocompatibility and so on. Furthermore, molecular imprinting polymers (MIP) can recognize the template molecules with a high specificity. Based on the situation mentioned above, we choose environmental hormones as target analytes, and the combination of the fluorescence properties of non-group II-VI quantum dots and the recognition properties of molecularly imprinted technique can provide highly selective and sensitive ratiometric fluorescence probe for target analytes.

环境激素广泛存在于环境中，在极低的浓度下也会对人、畜及生态环境造成很大的危害。目前，环境激素类物质的检测方法主要是色谱技术，这些方法灵敏度高、选择性好，但仪器昂贵，样品前处理繁琐。因此，急需发展一些简单、灵敏、快速的环境激素类物质的分析方法。比率荧光传感器具有简单，灵敏，低成本等优点，已成为测定痕量污染物有力的工具。更为重要的是，比率荧光探针能提供一个背景荧光信号从而实现可视化检测。据我们所知，基于量子点的比率荧光探针用于环境激素类有机大分子的检测还未见报道。与传统II-VI族量子点和荧光染料相比，非II-VI族量子点具有优异的光学性能和良好的生物相容性等优点。此外，分子印迹聚合物对模板分子具有灵敏的识别能力。为此，我们以环境激素为靶标分子，结合非II-VI族量子点荧光响应的灵敏性和分子印迹技术的高选择性，制备比率荧光探针，从而建立环境激素类物质高选择性、高灵敏的可视化分析方法。

环境激素类物质的检测方法主要是色谱技术，这些方法虽然具有较高的灵敏度和较好的准确性，但其前处理过程复杂、耗时，且设备昂贵，需要专业人员进行操作，因此其广泛应用受到了限制。因此仍需开发快速、简便、灵敏和低成本的环境激素类物质的检测方法。本项目我们结合量子点的发光特性、分子印迹技术、表面功能化设计和传感器组装技术，发展高灵敏、高选择性的环境激素类有害物质的量子点光学传感新方法，探讨其作用机理。主要的成果与进展包括：（1）采用微波、超声和水热等方法，合成制备了Mn掺杂ZnS、Si量子点、Au纳米簇和碳点等一系列高性能量子点，通过TEM、XRD、Vis-UV光谱、红外光谱、荧光光谱等手段对其结构进行表征。（2）建立了一种基于Mn:ZnS QDs-Cu2+体系的室温磷光探针测定焦磷酸根离子的新方法。（3）以邻苯二甲酸二丁酯(DBP)为模板，甲基丙烯酸（MAA）为功能单体、乙二醇二甲基丙烯酸酯（EDMA）为交联剂，在Mn掺杂的ZnS量子点表面合成了邻苯二甲酸二丁酯的分子印迹层，结合室温磷光检测技术实现对水体中邻苯二甲酸二丁酯的检测。（4）基于不同荧光发射的Si量子点和Au NCs，结合分子印迹技术，制备了SiQDs@SiO2-AuNCs MIP复合物，构建了用于检测BPA的比率荧光传感探针，并初步实现了可视化检测。有关研究为新型表面分子印迹传感器的研制提供了多种设计思路与制备方法，将有力地推动量子点比率荧光传感、分子印迹技术在环境分析、生命科学等领域的应用与发展。