有机小分子深红/近红外荧光材料的合成及其在生物荧光成像方面的应用

Organic small molecular far-red/near-infrared fluorescent materials have gained wide applications in the field of organic light-emitting diodes, biological fluorescent probes and imaging. The design and synthesis of the corresponding materials have been received considerable interest and widely attention. However, organic small molecular far-red/near-infrared fluorescent materials with high solid fluorescence quantum yield, that for practical bioimaging is still relatively limited and scarce. Therefore, in this project, we will employ the aggregation induced emission effect and the cruciform-crossed configuration strategy to achieve organic small molecular far-red/near-infrared fluorescent materials with high solid fluorescence quantum yield and two-photon absorption cross-section. We will start with the synthesis of different symmetric electron-deficient AIE core, and then develop a family of far red/near-infrared organic small molecule AIE effect fluorescent materials, that having high fluorescence quantum efficiency, high two-photon absorption cross section, by using the efficient palladium catalyzed coupling reactions. Secondly, we will investigate single photon/two-photon excited fluorescence imaging by using our organic small molecular far-red/near-infrared fluorescent materials to achieve high resolution, low cytotoxicity, and high regioselectivity of stain during cell imaging applications. Finally, we will investigate the influence of various modulated factors of our far-red/near-infrared organic small molecule fluorescent materials on the compatibility and regioselectivity of stain during cell imaging applications to find the structure-properties relationship and the design principle of organic small molecular far-red/near-infrared fluorescent cell imaging materials.

有机小分子深红/近红外荧光材料在有机电致发光二极管、生物荧光探针和成像等领域都有广阔的应用。相应材料的设计与合成受到国内外科学家的广泛和持续的关注。然而具有高固态荧光量子产率的小分子深红/近红外细胞荧光成像材料种类还比较匮乏。本项目拟利用聚集诱导发光效应和支化的十字交叉构型策略来实现有机小分子深红/近红外荧光材料的高固态荧光量子产率和高双光子吸收横截面。拟从合成三类不同对称性的十字交叉型的缺电子AIE母核入手，利用高效的钯催化偶联反应，发展十多种结构规整的十字交叉型的AIE小分子深红/近红外荧光材料，使之具有高固态荧光量子效率、高双光子吸收横截面等特点。最后我们将其应用到单光子/双光子激发的细胞成像中，实现高的成像质量、低毒性和特异性识别等优点。探讨各种因素对细胞成像中的材料和生物体的相容性和特异性识别等性能的影响和构效关系。建立小分子深红/近红外荧光细胞成像材料的设计原则。

聚集诱导荧光材料的设计与合成受到国内外的广泛和持续的关注。然而用于化学荧光探针和生物荧光成像等领域高固态荧光量子产率的小分子AIE材料种类还比较匮乏。在本项目中以“荧光光谱拓宽至红光区的AIE小分子材料合成及其在荧光探针和生物荧光成像等领域中的应用”为研究中心，合成了基于四苯基乙烯、二苯基二噻吩乙烯、更富电子的四噻吩乙烯核心的AIE小分子材料，对其在力致变色、光波导，光致变色、化学荧光传感、细胞内荧光成像等方面的应用做了深入系统的研究。获得了低光波导耗损系数的光波导材料、肉眼识别的超大荧光红移程度的力致变色材料以及紫外光光致变色材料。实现了低毒性的优异光稳定性的红色细胞膜特异性荧光成像。实现对三价金属离子在细胞内外的选择性识别和荧光传感成像以及可逆性的酸致变色行为。实现了对毒性较大的水合肼溶液、固态滤纸条的高效荧光检测，以及对亚硫酸氢根的荧光淬灭型检测。实现了对次氯酸根的反应型化学荧光传感检测和细胞内源次氯酸根的生物成像检测。得到了材料分子结构中的共轭桥的种类、给电子或缺电子端基的数目以及位置等精细结构调控对材料光物理性质和各方面应用的影响的规律和相应的分子结构与材料性能的构效关系，提出了该类AIE材料体系的设计原则，顺利的完成了相应的研究目标，取得了一系列有特色的科研成果。到目前为止，已发表以北理工第一通讯作者单位或第一作者的高水平论文有24篇(均含有本基金号标注，其中20篇的IF>6)，包括Energy Environ. Sci. (1篇), ACS Energy Lett (1篇), J. Mater. Chem. A (4篇), Chem. Mater. (1篇)等。其中有4篇文章发表以后成为热点文章或者当月浏览量前10名之一。另外还有2篇高水平论文在整理中。项目执行期内培养研究生和年轻科研骨干10名获得学位，其中包括4名博士生和3名硕士生。