基于荧光素半菁-CuInS2量子点的丙氨酸氨肽酶活性纳米传感器的设计及应用

酶参与多种生理活动，实现对其活体、原位、实时的准确定性和定量，是目前化学测量学中亟需解决的重大问题。为了解决利用光谱法检测酶时存在的Stokes 位移较短、散射信号强、背景干扰较大等缺点，本项目拟利用现代有机合成技术，通过含时密度泛函理论（TDDFT）计算和分子动力学模拟，设计合成对于丙氨酸氨肽酶（APN）具有特异性识别能力的荧光素半菁染料作为能量受体，通过共价键与能量供体CuInS2量子点结合，搭建荧光共振能量转移（FRET）纳米传感器，实现对APN的高灵敏、选择性检测，并将其应用于药物性肝损伤模型、肝癌模型和体内荷瘤小鼠模型的APN活性成像，揭示APN在肝功能中的重要性及其在肝病诊断和治疗中的潜在价值，探究酶在特定生理过程和疾病进程中的含量变化，为APN在生理活动中的作用机理研究提供技术支持。

Enzymes, which involve in various physiological processes, play an important role in disease diagnosis and clinical treatment. As a result, achieving accurate qualitative analysis and quantification in vivo, in situ, and real-time is a major challenge that needs to be solved in current chemical surveying. Although, fluorescent probe is an optimum choice for such detections, it usually contains several disadvantages, for instance short Stokes-shift, strong scattering signal, large background interference, and so on. To overcome these shortcomings, in this project, organic dyes-quantum dots composite fluorescent probe with near infrared luminescence, ratio response, low background interference, stable chemical properties and biological compatibility will be prepared and screened by using modern organic synthesis technology. In the first place, by utilizing the theory of time-dependent density functional theory (TDDFT) and molecular dynamics simulation, near-infrared fluorescein hemi-cyanine dyes with high specific recognition ability for alanyl aminopeptidase (APN) will be designed and synthesized. Secondly, taking advantage of organic dyes and quantum dots based on our previous research, the fluorescence resonance energy transfer (FRET) nano sensors for the highly sensitive and selective detection of APN will be constructed by covalent bonding CuInS2 quantum dots with organic dyes in which the dye will be used as an energy acceptor that can conjoint with the energy donor (CuInS2 quantum dot). In addition, a serious of research should be conducted around the sensor, such as its application to image the APN activity in a drug-induced liver injury model, liver cancer model and in tumor-bearing mice model in vivo, revealing the importance of APN in liver function and its potential value in hepatopathy diagnosis and therapy. To investigate the content changes of enzyme in specific physiological and disease processes, and providing technical support for the study of the mechanism of action of APN.