基于荧光染料FRET体系的构筑及对血清胆固醇定量检测研究

Serum cholesterols are the fatal risk factors for cardiovascular diseases. The widely used enzymatic method for cholesterol determination is complicated and deflected. Therefore, how to determine low-reactive cholesterol directly is a key scientific issue of our project. .This project will start with the recognition mechanism between Host and Guest: 1) Employs cyclodextrin (CD) as an encapsulating unit for cholesterol (Chol). 2) Introduces fluorescent group as a donor via chemical bond, and introduces hydrophilic AIE molecule as an acceptor via van der Weals force, regulates donor-acceptor spectra and distance, and constructs a high-efficiency förster resonance energy transfer (FRET) system AIE@CD-Fx. 3) Based on dynamic comparison of binding constants of “Host-Guest”, optimizes the size of host CDs and the hydrophily of guest AIE molecules, screens for optimal host-guest molecules, enable cholesterol to replace AIE molecule in cyclodextrin, with the generation of Chol@CD-Fx. The rapid and quantitative detection of cholesterol will be addressed by the ratiometric response of dual-channel fluorescent signals of FRET, which provides a new strategy for the determination of low-reactive cholesterol in complex physiological environments.

血脂胆固醇升高是心血管疾病最重要的风险因素，目前广泛使用的酶法检测胆固醇操作复杂、结果偏差大，因此如何对低反应活性物胆固醇直接定量检测是本项目的关键科学问题。. 本项目创新性地从主客体识别机制入手：1）引入环糊精（CD）作为胆固醇（Chol）特异性识别单元；2）通过共价键引入能量给体荧光团（Fx），通过分子间作用力套入受体水溶性聚集发光AIE分子，调控给体与受体光谱匹配度及距离，构筑高效荧光共振能量转移（FRET）体系AIE@CD-Fx；3）基于主客体包络力动力学比较，优化主体环糊精尺寸与客体AIE分子亲疏水性，筛选出最优主客体分子，使胆固醇得以顺利置换环糊精内AIE分子由AIE@CD-Fx生成Chol@CD-Fx，FRET切断。通过FRET双通道荧光信号的比率型响应实现胆固醇的快速定量检测，为复杂生理环境下低反应活性物胆固醇的定量检测提供新的方法。

荧光共振能量转移是一种经典的能量传递方式。经过三年的努力，我们基于聚集诱导发光染料成功构筑了多种荧光共振能量转移体系。通过将荧光能量供体修饰成液晶或液体，能够有效提高传递效率，最高可达95.1%。在构建FRET体系过程中，我们不仅从发光角度讨论其能量传递，也考虑到非辐射能量耗散（发热），部分FRET体系中，可产生明显光热，光热温度达到119℃。另外，因为广泛采取手性液晶基元胆固醇对荧光基团进行修饰，通过手性液晶组装甚至诱导出手性的圆偏振发光，具有良好的器件显示与生物高分辨成像潜力。通过荧光共振能量转移，手性给体可以诱导非手性受体发射手性荧光，进一步丰富其内涵，我们将这种现象命名为手性荧光共振能量转移。在本项目执行期间，累计发表SCI研究论文7篇。.同时，本项目正在围绕荧光素/尼罗红-环糊精FRET体系对多种胆固醇进行水相测试，相关成果暂未公开发表。