荧光薄膜光漂白缓解新策略

For the real-life application of a fluorescent sensing film-based “photonic nose” or “photonic tongue”, it is a pre-requirement that the film or the film device should be photochemically stable. However, for most of the fluorescent organic compounds or materials, they are not stable under long-term photo-illumination due to photobleaching, a result of chemical reaction at excited state of the compound or the materials. To the best of our knowledge, the methods or strategies till now used for improving the photochemical stability of fluorescent materials are limited, and thereby it still remains a great challenge to understand the details of a photochemical degradation process, and to develop new strategies or methods for improving the photochemical stability of a fluorescent material in a broader horizon. Therefore, based on the review and summarization of the relevant work conducted in our lab and that in other labs, as well as the structure of the photosynthetic reaction center of green plants, it is proposed that physical isolation of fluorescent units may be helpful for the inhibition of photochemical degradation or photobleaching. In consideration of the creativity of the ideas described above and the fact of the relatively ordered and uniform structure of the gelator networks of molecular gels, it is decided to design and synthesize more than 30 fluorescent derivatives possessing the structural characteristics of low-molecular mass gelators, of which some aromatics or oligo-silanes will be adopted as core-structures, and sugars, alkanes and cholesterol as auxiliary units. It is anticipated that for each of the fluorescent derivatives, at least one networked structure will be obtained via utilization of a molecular gel strategy, and furthermore within the network the fluorescent unit of the compound should be physically isolated. The fluorescent networks as created will be transferred onto substrate surfaces and used as model materials to study if photobleaching could be blocked or inhibited by the physical isolation of the fluorescent units. Through this effort, it is believed that a new and general strategy will be established which may be used for creating fluorescent sensing films with improved photochemical stability and enhanced sensing performances.

光化学稳定是薄膜基“光子鼻（舌）”获得应用的基础，光漂白是影响薄膜光化学稳定性的主要因素。然而到目前为止，光漂白机理和缓解策略研究还仅限于少数荧光物质。因此，以更宽广的视野理解光漂白过程，发展光漂白缓解策略依然是科学界面临的一大挑战。本项目在归纳总结申请者团队和他人工作，分析绿色植物光合作用系统结构的基础上，提出以荧光单元的物理隔离实现光漂白作用缓解这一思想。据此并考虑到分子凝胶中胶凝剂分子多以多孔网状有序聚集结构存在，为此拟通过系列荧光活性小分子胶凝剂的设计合成，借助分子凝胶和基质担载构建荧光单元相对隔离、孔道结构丰富、稳定性好、基质表面粘附性高，可同时用于气液（水）两相研究的荧光薄膜材料。在此基础上，研究荧光单元物理隔离对光漂白作用缓解的有效性和可能的缓解机理，以期发展一种具有一定普适性的光漂白作用缓解新策略和高性能荧光传感薄膜材料创制新方法，为该类材料的创新制备和高性能化做出贡献。

光化学稳定是薄膜基荧光传感器获得应用的基础，光漂白是影响薄膜光化学稳定性的主要因素。围绕这一关键科学问题，项目组依据荧光物质在溶液态的光化学稳定性显著优于在紧密堆积条件下的固态光化学稳定性这一事实，通过控制荧光物质固态聚集形式显著改善了荧光物质的光化学稳定性。提出并发展了荧光敏感薄膜创新制备的分子凝胶策略和集毛细作用、微环境敏感性和解吸动力学于一身的组合设计策略，发展了一系列光化学稳定性好、传感灵敏度高、可逆性可满足实际检测需要的新型荧光薄膜材料。基于此，发明了高性能概念性BTEX等薄膜荧光传感器。项目进行期间，发表研究论文25篇，获授权发明专利4件；出版《薄膜基荧光传感技术与应用》专著1部；培养博士毕业生6名，其中王刚博士入选国家博新计划，鱼春萌博士的学位论文获评陕西省优秀博士论文。