有机挥发性气体及有机液体检测的荧光传感薄膜创制及性能研究

Volatile organic compounds and organic liquids are one of the well-known pollutants in the atmosphere and water system. They not only endanger human health, living environment, but also affect the sustainable development of the community. The currently developed detection systems suffer from various disadvantages including weak capacity of discrimination, secondary pollution, and poor reversibility. To solve these problems, we aim to design novel solvatochromic molecules and chemically immobilize them to the surface of solid substrates. We propose to introduce different conjugate fragments and terminal functional groups to the probe molecules to obtain a series of novel fluorescent derivatives with complementary photophysical properties and solvatochromic emission range to realize visual detection of different types of organic molecules. The attachment of solvatochromic probes on the solid matrix is realized via self-assembled monolayer technique. The discrimination of volatile organic compounds and organic liquids from each other is achieved by the different interactions between solvatochromic probes and analytes and the changes of excited-state level of probes. In this project, we will design and fabricate a variety of film sensors with versatile performance via tuning the length and flexibility of the spacer of the substrate surfaces based on the two dimensional SAM film chemical theory, in order to neatly regulate the adsorptive capacity of the film to different kinds of volatile organic compounds. We will construct a variety of high efficient fluorescent sensor arrays for visual distinction of different categories volatile organic compounds and organic liquids. The implementation of this project will have important impact on theoretical research and practical application.

有机挥发性气体及有机液体类物质是造成大气及水体污染的主要因素之一，危及人类和动植物的生存环境，不利于社会的可持续发展。针对目前检测体系存在的区分度低、容易造成二次污染、可逆性较差等问题，本项目拟通过特定的溶致变色分子设计并将其化学修饰至固体基质表面来解决。通过在探针分子中引入不同共轭片段及末端功能基，设计合成系列光物理性质互补且具有不同溶致变色范围的探针实现对不同类别有机分子的可视化检测。采用自组装单层膜技术将探针分子经表界面化学反应键合于固体基质表面创制荧光传感薄膜，基于有机分子与薄膜表面相互作用的不同和对探针激发态能级结构的改变实现可视化检测。通过改变基质表面连接臂的长度、柔性及亚结构调控薄膜表面的分子通道，改善其对不同种类挥发性气体的吸附或“亲和”能力，构筑高效的荧光薄膜传感器阵列。该项目的顺利实施将为有机挥发性气体及液体的检测开创新的方法和设计思路，在理论和实际应用中具有重要意义。

有机挥发性气体及有机液体类物质是造成空气质量下降和水体污染的主要因素之一，危及人类和动植物的生命健康。溶致变色荧光探针由于其光物理或光化学性质对所处介质的极性或结构非常敏感，作为一类高效的用于区分和检测有机液体及挥发性有机气体的传感单元，逐渐受到科学工作者的关注。基于此，本项目通过将特定结构的溶致变色分子经化学或物理方法修饰至固体基质表面创制高效的荧光传感薄膜实现对上述分析物的可视化检测。依据项目研究计划，研究内容概况为以下三方面：（1）通过改变电子供体和电子受体在苯环上的相对位置和数量设计合成系列光物理性质互补且具有不同溶致变色范围的单苯环类荧光小分子；（2）基于一种新型脱甲基化反应获得具有不对称结构的四取代单苯环类荧光探针，探针分子在粉末态和不同极性溶剂体系具有较高的荧光量子产率和显著的溶剂依赖性；（3）将溶致变色小分子进一步功能化制备的荧光传感薄膜及探针分子实现了对挥发性有机气体、有机液体等环境敏感物的灵敏检测。整个过程中，结合实验和理论模拟的方法对不同系列荧光单元在不同溶剂体系的激发与发射过程进行了系统研究，采用荧光传感及表界面化学理论对检测机理进行了深入探索，为新型溶致变色荧光小分子的基础及应用研究奠定了一定基础。目前已完成项目的预期目标，在后续工作中，将继续聚焦于荧光传感薄膜的创制及界面自组装结构的改进。