基于碳点的高分子纳米粒子的制备及其对内源性生物物质的荧光检测与示踪

内源性生物活性物等具有重要的生理和病理作用，对一些内源性生物物质的荧光检测可为重大疾病的发生和发展提供判据，并为临床治疗提供有效信息。为了克服在该领域尚存的一些问题，本研究拟以碳点和/或高分子基体为能量供体和检测体系的载体，将含识别基团的嵌段共聚物连接到碳点表面，构建一系列基于FRET原理的不同生物物质的分析体系。通过对聚合物分子链、识别基团及其与大分子之间的间隔基的合理设计，并对体系的相互作用进行有效控制，实现高效的酶促反应和能量转移过程。获取不同个体的生理液样本，对特定生物物质的浓度进行荧光比率检测，考察体系对实际样品检测的准确性和专一性。研究并优化体系的细胞毒性和细胞膜透过性，探讨荧光检测体系对活细胞内生物物质的荧光成像，以反映胞内生物物质的浓度水平。通过本项目的开展，我们希望能掌握荧光粒子/含荧光生色团大分子体系中能量转移行为及检测功能的调控方法，实现对内源性生物物质的高效检测，从而拓展高分子体系的应用范围。

Endogeous bioactive substances including metabolic enzymes are of great significance in terms of physiological functions and pathological roles. Fluorescent sensing and tracking of metabolic/diagnostic enzymes are helpful for disease diagnosis as well as searching for effective treatments. In order to address the existing issues in this field, herein we plan to employ carbon dot as both the energy donor and the anchoring site for the recognition-chromohpore containing polymer; the said polymer consists of two blocks, one block contains the recognition moieties (namely the recognition-chromophores, which can serve as the energy acceptor upon reaction with specific metabolic enzyme depending on the structure of the recognition moiety), while the other block is hydrophilic and biocompatible, thus a series of FRET systems can be constituted for diagnostic enzymes. Through rationally designing the polymer chain structure, the chromophore structure, as well as the spacer between polymer chain and recognition moiety, in the mean time by modulating the interactoins of the system, highly efficient enzymatic reactions and energy transfer can be realized. Furthermore, we will apply the fluorescent sensing systems to various biological samples, so as to detect specific enzyme levels via fluorescent ratiometric sensing, and investigate the systems' accuracy and specificity. In addition, we will optimize the systems' cytoxicity and cell membrane permeability, and invesitgate their potential for intracellular imaging of metabolic enzymes and sensing intracellular enzyme levels. This study will offer effective approaches for modulating the energy transfer behavious and sensing functions of the particle/chromophore-containing polymer systems, as well as for realizing sensitive detection of metabolic enzymes, and thus extend the applications of polymeric systems.