基于聚集诱导发光的有机双光子荧光传感器

A series of symmetric quadrupolar and hyperbranched compounds were synthesized with D-π-D、D-π-A and A-π-A structures as the core, silacyclopentadiene and tetraphenyl ethylene based triphenylamine derivatives as the electron donors, and diketopyrrolopyrrole, naphthalene tetracarboxylic imide, perylenediim, tetracene imide and naphthalene imide perylene imide as electron acceptors. The two-photon absorption cross section and photoluminescence intensity of the compounds were significantly improved through electron delocalization interaction and synergies between the chromophores. The obtained material had high performance in two-photon fluorescence and aggregation-induced emission (AIE) properties. The AIE, two-photon absorption and two-photon fluorescence were studied. In further step, the compounds with two-photon fluorescence and AIE properties were chemically modified by introducting light, pH, ion or solvent sensitive groups. The two-photon fluorescence properties of the fluorescent sensor would be changed with the changing of external environment, which can be used to detect the external environment. Water-soluble pyridine salt, quaternary ammonium salt and sodium salt of diketopyrrolopyrrole and tetracene imide derivatives with AIE and two-photon fluorescence probes were explored to label and detect biologically active molecules and HeLa、KB、MCF-7 cells.

利用D-π-D、D-π-A和A-π-A结构作为双光子材料的基本骨架，以具有聚集诱导发光（AIE）特性的硅杂环戊二烯和四苯基乙烯三苯胺为电子给体，吡咯并吡咯二酮(DPP)、苝酰亚胺、并四苯酰亚胺等强荧光基团为电子受体，创新合成一系列对称四极结构和多枝状化合物，利用各个发色团之间存的电子离域相互作用和协同增加效用，显著提高化合物的双光子吸收截面和荧光量子效率，得到具有AIE特征的双光子荧光材料，并对化合物的AIE、双光子吸收和双光子荧光性能进行研究；把筛选出的具有AIE特征双光子荧光化合物作为基本骨架，进行化学修饰，引入对光、酸碱或离子敏感的基团，获得根据外界环境变化而改变双光子荧光性能的荧光传感器，实现对外部环境的检测；探索开发水溶性DPP和并四苯酰亚胺等衍生物的吡啶盐、季胺盐及磺酸钠盐的AIE特征双光子荧光传感器，实现对生物活性分子和HeLa、KB、MCF-7等细胞的的高效荧光标记及检测。

（1）设计合成了一系列以吡咯并吡咯二酮（DPP）、均三嗪、菲醌喹喔啉、吡啶噻二唑为电子受体的D-π-A-π-A-π-D电子结构的大共轭体系，这些化合物在四氢呋喃溶液中几乎不发光，但在聚集态及固体状态分别发出很强的近红外和红色荧光。基于DPP固体发射波长分别在780 nm和660 nm，双光子吸收截面分别可达到10600 GM和8100 GM；带有苯乙腈结构的DPP具有较高的固体荧光量子产量可达到11.3%，将其纳米颗粒应用于小鼠耳朵组织的双光子荧光成像中，可以通过标记的染料清楚的看到组织中的血管；.（2）以二苯并吩嗪基元为电子受体、甲氧基取代的三苯胺基元为电子给体，构筑了具有D-A结构的可用于溶血磷脂酸（LPA）检测的近红外荧光探针体系TDB。通过其与LPA具有较好的疏水作用和静电作用，形成了溶解性较差的大分子，从而聚集产生了相应的荧光响应，其检测限为4.47×10-7 M。.（3）设计并合成了以甲氧基三苯胺修饰的 DPP为 AIE 荧光团，甘露糖基和半乳糖基作为识别基团的近红外荧光探针，通过糖-凝集素的相互作用，诱导糖基化分子发生聚集，利用荧光增强信号分别实现了对甘露糖特异性识别伴刀豆凝集素，小扁豆凝集素和半乳糖特异性识别花生凝集素的检测，对凝集素的检测限达到了纳摩尔级别，有望被应用到凝集素过表达组织的低背景干扰的活体成像中；.（4）开发了以三苯胺修饰的DPP和四苯乙烯（TPE）作为荧光团，对称二酰胺吡啶盐作为识别基团的具有聚集诱导发光（AIE）效应的荧光化学传感器，这些探针对柠檬酸表现出良好的选择性和灵敏度，并具有较低的检测限为1.0×10-7。该方法操作简单，成本低，检测迅速，为血清中检测重要小分子提供了新的思路。.（5）本项目在 Adv. Funct. Mater., Biosens. Bioelectron., Chem. Commun., Anal. Chem., J. Mater. Chem. C, J. Mater. Chem. B, Talanta等国际重要知名期刊发表了59篇论文。申请发明专利6项，其中4项已授权。培养研究生15名。