近红外“ESIPT+AIE”型β-半乳糖苷酶荧光探针的构筑及生物成像研究

β-Galactosidase (β-Gal) is an important biomarker for primary ovarian cancers. Therefore, the development of highly sensitive detection and imaging method for β-Gal activity in the body is thus of great importance and offer great application prospects. In recent years, organic fluorophores with aggregation-induced emission (AIE) feature exhibit highly bright fluorescence when aggregated, and weak fluorescence when separated in solution, making them beneficial for improving the sensitivity of biosensors and bioimaging in vivo. However, most AIE-active fluorophores used for β-Gal detection have emission wavelengths below 650 nm, which limit the further practical applications involving in vivo researches that need low autofluorescence and deep penetration. Based on the above considerations, a series of near-infrared (NIR) fluorophores with excited-state intramolecular proton transfer (ESIPT) and aggregation-induced emission (AIE) characteristics is rationally designed by attaching the electron-donor hydroxyl benzothiazole (HBT) and the electron-acceptor benzyl cyanide derivatives (BCn). Through the strategy of protection–deprotection of the phenolic hydroxyl group, the novel fluorophores will be employed to develop NIR β-Gal fluorescence probes with both ESIPT and AIE features. By using these NIR “ESIPT + AIE”-based probes, a novel method for the high sensitive and selective detection ofβ-Gal will be established. Combined with the fluorescence imaging technique, high-resolution tracking and visualizing β-Gal activity in live cancer cells and in vivo will be realized. Our research will offer one excellent method and technology for tracking β-Gal activity in early disease diagnosis.

β-半乳糖苷酶（β-Gal）是原发性卵巢癌的一种重要生物标志物。因此，研发高效的检测手段对生命体系中β-半乳糖苷酶进行成像与定量，对卵巢癌的精确诊断具有重要意义。聚集诱导发光（AIE）化合物具有高效的发光效率，可以很好地提高生物传感与成像的灵敏度，因而受到广泛关注。然而，目前报道用于β-Gal检测的AIE荧光分子其发射波长主要集中在紫外和可见光区，存在背景光干扰和光穿透性低的缺陷，很难实现机体内较深层处β-Gal的成像研究。基于此，本项目拟将电子给体苯并噻唑与电子受体苯乙腈类化合物通过共价键连接，合成系列兼具激发态质子转移和聚集诱导发光（ESIPT + AIE）性质的近红外β-Gal荧光探针；利用近红外荧光、ESIPT和AIE发光效应的多重优势，建立一种灵敏、可靠的β-Gal荧光检测方法；结合荧光成像技术，实现对细胞及活体中β-Gal的高分辨荧光成像，为卵巢癌的早期诊断提供有力的工具。

重大疾病的发生和发展都会伴随着相关指标物质浓度或者活性的变化，检测体内生命健康指标物质对相关疾病的病理研究、早期诊断与治疗具有重要意义。聚集诱导发光（AIE）化合物具有高效的发光效率，可以很好地提高生物传感与成像的灵敏度，因而受到广泛关注。然而，大多数报道的探针激发或者发射波长位于紫外-可见光区，存在光漂白、生物自发荧光的干扰和对生物细胞光毒害等缺点，不利于的生物应用。本项目通过选择合适的荧光化合物（苯并噻唑、异佛尔酮、二氰基甲基-4H-吡喃衍生物）和调控分子内推拉电子作用，并利用有机反应机制，构建系列新型荧光探针，解决了传统探针存在聚集诱导淬灭效应、发射波长短、Stokes位移小等问题，实现健康标志物（β-半乳糖苷酶、ONOO-、HClO、H2S、Cu2+等）在生物体内的可视化检测，为细胞内重要生物小分子的高灵敏、原位检测提供了新方法，对促进生物传感和分析化学的发展起到积极作用。在项目资助下，发表SCI论文6篇（其中1区3篇，2区3篇），申请发明专利2项，培养硕士研究生2人。