基于氧杂蒽染料的比率型重金属离子荧光探针的合成及应用

Pollution of the environment by heavy metal ions and its harm to the health of life have attracted much attention. In recent years, ratiometric fluorescent probes with the function of detecting heavy metal ions have been widely studied because of their excellent sensitivity and accuracy. However, the detection and identification of ions by most fluorescent probes are via single channel signal, which is sensitive to the interference by the environment. To overcome this drawback, ratiometric xanthene molecules with different energy donors were constructed as probes by using the fluorescence energy resonance transfer mechanism. In these probes, the new xanthene dye was used as the energy acceptor, and fluorescent chromophores matching the absorption band of xanthene receptor molecule were used as the energy donor. The detection and identification of target ions in water body and organisms with multi-channel signals were realized, by using the change of color and fluorescence caused by electron, charge or energy transfer before and after ion complexation. Moreover, the energy transfer efficiency among different fluorescent chromophore groups and xanthene molecules was studied by introducing different fluorescence groups with different emission wavelengths. Furthermore, the probe molecules with specific recognition of heavy metal ions were synthesized through structural modification, and the recognition mechanism between the end modification groups and heavy metal ions was studied. This work will expand the application scope of ratiometric fluorescence probes and provide a new strategy for the detection and identification of heavy metal ions.

重金属离子对环境的污染和生命体健康的危害备受关注。近年来，具有重金属离子检测功能的比率型荧光探针由于其优异的灵敏度和准确性成为研究的热点之一，但目前该类探针对离子的检测识别大多是单通道的，抗干扰性差。鉴于此，本课题利用荧光能量共振转移机理，以新型氧杂蒽染料为能量受体，通过在氧杂蒽受体分子中引入与其吸收波段相匹配的荧光发色团作为能量供体，构建具有不同能量供体的比率型氧杂蒽探针分子，利用其在离子络合前后电子、电荷或能量转移导致的颜色和荧光的变化，实现探针在环境水体和生物体内对目标离子颜色和荧光的多通道信号的检测识别。一方面，通过引入不同发射波长的荧光团，研究荧光发色团与氧杂蒽分子之间能量转移效率的关系；另一方面，通过对探针分子进行结构修饰，研究末端修饰基团对重金属离子的识别机理。本工作将拓展比率型荧光探针的研究范围，为重金属离子的检测识别提供新的设计思路和方法。

荧光探针是近年来在离子检测领域兴起的一种新方法，其在灵敏度、选择性、响应时间、原位观测等方面具有显著的优点。特别在过去的几十年中，荧光显微技术和时间分辨技术的得到迅速发展，基于荧光技术在生命科学领域发挥着越来越重要的作用，荧光探针现已成为研究生物学和基础医学领域相关问题的重要工具，开发对重金属离子具有高选择性和高灵敏度的荧光探针具有重要的理论和应用价值。目前，大部分荧光探针对离子的检测识别是单通道的，对检测环境影响的抗干扰性差。因此，如何在现有的“单一”增强型荧光探针的基础上，设计合成具有“双通道”荧光信号变化的比率型氧杂蒽荧光探针，成为当前倍受关注、急需解决的研究课题。本项目利用荧光能量共振转移机理，以新型氧杂蒽染料为能量受体，采用化学合成的方法，通过在氧杂蒽受体分子中引入与其吸收波段范围相匹配的荧光发色团作为能量供体，构建具有不同能量供体的比率型氧杂蒽探针分子。在本项目的支持下共合成了30余种“双通道”荧光信号变化的比率型荧光探针分子，系统的研究了其对不同分析物的光学检测性能，并筛选出性能优异的目标分子初步应用于细胞荧光成像领域，发表SCI论文29篇，国家发明专利授权2项。本工作拓展了比率型荧光探针研究范围，为“双通道”荧光信号变化的荧光探针分子研究提供新的设计思路及应用研究基础。