基于碳点的生物硫醇纳米荧光探针的构建及应用

Selective recognition of biothiols is critical for understanding the formation process of diseases and clinical diagnosis. The purpose of this project is to develop fluorescent nanoprobes for selectively detecting biothiols by using carbon dots (CDs) as fluorophore and surface functionalization of CDs with highly specific recognition element of biothiols through covalent bond. CDs with excellent fluorescence properties will be firstly synthesized using aromatic compounds with different substituent as carbon source, and selected through the.studies of their spectral properties and structures. Then, the recognition units of biothiols will be functionalized on the surface of CDs. The fluorescence signal will be manipulated by the strong nucleophilicity of the sulfhydryl group in biothiols and the synergistic effect of their sulfhydryl group and adjacent amine group. Thus, specific detection of biothiols can be realized. Compared with the existing fluorescent probe and nanoprobe based on CDs for detection of biothiols, the chemosensing system will greatly improve the photostability, biocompatibility and selectivity of optical probes. New strategies will be developed for selectively detecting biothiols in biological systems, which can broaden the application of optical probes in the field of life science.

选择性识别生物硫醇对研究疾病的形成过程和临床诊断具有非常重要的意义。本项目拟以新型碳点（CDs）为荧光团，通过共价键将不同功能的识别基团引入CDs表面，分别构建可专一检测生物硫醇总量、半胱氨酸（Cys）和谷胱甘肽（GSH）的纳米荧光探针。首先，以取代基种类和位置不同的芳香族化合物为碳源合成CDs，通过研究它们的光谱性能和结构组成，筛选出高荧光性能CDs为荧光团；然后，将2，4-二硝基苯磺酰氯、丙烯酰氯及2，4-二硝基苯酚类等识别基团引入CDs表面，利用生物硫醇中巯基的亲核能力及巯基与邻近氨基的共轭加成-环化作用，调控传感体系的荧光信号，实现目标分子的专一检测。与已有检测生物硫醇的有机荧光探针和基于CDs的纳米探针相比，本项目构建的纳米荧光探针有望大幅提高探针的光稳定性、生物相容性及选择性。同时，本研究为专一识别生物硫醇提供了新的思路，拓宽了光学探针在生命科学领域的应用。