分子纳米开关的设计和开发及生物酶活性水平的检测在临床诊断、疗效判断和疾病预后中具有重要的应用价值。基于光诱导电子转移机制的荧光纳米开关在生物传感器、示踪细胞成像、智能纳米药物等领域具有广阔的应用前景。本项目拟设计构建基于功能化碳量子点和光诱导电子转移机制的新型多功能纳米开关，将其用于构建检测多种生物酶活性的生物传感器，发展相关生物酶抑制剂的高通量筛选方法，并用于细胞内生物酶相关生理过程和细胞内环境的动力学变化的荧光实时监测。本项目拟从碳量子点纳米开关的理论基础、模块化设计与控制单元构建、纳米开关合成与组装、生物酶活性检测应用等四个方面探索和研究通过纳米开关的可控切换引起的荧光信号的变化，实现细胞或活体内生物酶水平高低的实时检测、具有酶活性抑制性能的药物分子的荧光跟踪和生物酶生理过程的可视化监测，并用于细胞和活体内的生物学评估研究，为构建相关疾病早期检测和治疗的多功能纳米器件提供基础和借鉴。

Design, development and the use of molecular fluorescent nanoswitches in the detection of biological enzyme activity are of great significance in practical application of clinical diagnosis, curative effect evaluation and prognosis of disease. Fluorescent nanoswitches based on photoinduced electron transfer show a great applicable prospect in biosensors, intracellular bioimaging and smart drug delivery systems. This project is to explore the applicability of block-based design principle from supermolecules in fluorescent nanoswitches, construct novel fluorescent nanoswitches using carbon quantum dots as the fluorophore based on photoinduced electron transfer mechanism, and further apply these nanoswitches to quantitative determination of relevant biological enzyme activity, high-output screening of inhibitors of enzymes, and real-time fluorescent monitoring of relating biological processes to the enzymes and dynamic changes of intracellular environment. This project is planned to contain four parts including basic principles of fluorescent nanoswitches based on functionalized carbon quantum dots, block-based design and control unit construction, synthesis and assembly of nanoswitches, and the application in relevant biological enzyme detection, effective screening of the inhibitors and real-time monitoring of relevant biological processes. Through these research works, it aims to utilize fluorescence change induced by controllable switching of the nanoswitches to achieve real-time detection of biological enzyme activity in living cells and organisms, fluorescent tracing of molecular drugs as the inhibitor of certain enzyme, and visual monitoring of specific biological processes relating to certain enzyme. These nanoswitches and biosensors will be further biologically evaluated in living cells and organisms, and would pave the way and provide a preliminary investigation for multiple-functional devices targeting at early diagnosis and accurate treatment of relevant diseases.