基于二硫化钼量子点的上转换荧光特性建立快速检测微囊藻毒素的新方法

The fluorescence spectrometry has many advantages such as simple operation, low cost and high sensitivity, therefore, it is suitable for rapid and on-site real-time analysis. However, the background interference during fluorescence measurements usually brings analysis results serious distortion. In this project, molybdenum disulfide quantum dots with the upconversion fluorescence which can effectively avoid the background interference are used as signal molecules, and the nucleic acid aptamers with high specificity and affinity are used as the targeting recognition. The project aims to the fabrication of a fluorescent sensor for the detection of microcystin (MCs) with rapid, high sensitivity and high selectivity based on the inner filter effect (IEF) between molybdenum disulfide quantum dots and gold nanoparticles. The mainly contents conclude something as the followings: Molybdenum disulfide quantum dots with upconversion fluorescence, high quantum yield and good stability were synthesized by a facile hydrothermal method, and characterized by HRTEM, SEM, FTIR, AFM, XPS and Raman spectra; The novel fluorescent sensing sensor for the detection of MCs will be constructed based on IEF between molybdenum disulfide quantum dots and gold nanoparticles; The construction and detection mechanism of the sensor platforms will be studied; The detection performance for MCs in system will be explore. This proposed project will clarify the relation between the interface reaction of functional nanomaterials and the sensing mechanism and reveal their sensing mechanism. The implementation of this project has important theoretical and practical significance to enrich and develop the rapid detection method of MCs.

荧光分析法简单、成本低、检测灵敏度高，然而，易受基体自动荧光背景的干扰，导致分析结果失真。本项目利用能够有效避免背景荧光信号的上转换荧光二硫化钼量子点作为信号分子，核酸适配体作为靶向识别分子，构建基于内滤效应（IEF）的新型荧光传感器体系，用于微囊藻毒素（MCs）的快速、高灵敏度及高选择性分析。主要内容包括：高量子产率和稳定性好的上转换荧光二硫化钼量子点的设计合成；构建基于二硫化钼量子点（信号探针）与纳米金（吸光体）IEF体系，研究二硫化钼量子点与纳米金的组成及结构等对IEF的调控机制、反应动力学及光子转移机理；探索核酸适配体和二硫化钼/纳米金传感体系对MCs的分析特性；在此基础上，阐明功能化纳米材料及其界面反应过程与传感机制之间的内在关系，实现纳米传感器的性能调控。本项目的实施有助于丰富和发展MCs的快速检测方法，有重要理论和实际意义。

环境水体中微囊藻毒素(MCs)因其难降解和强致癌性对人类的生命安全造成了威胁，对其快速和灵敏检测意义重大。适配体荧光传感器可以克服传统检测分析方法成本高、易失活、不利于现场检测的缺点。但是MCs本身结构不存在直接影响荧光基团发光的因素，因而寻求功能化荧光纳米材料结构与目标物性能之间的构效关系成为目前研究的瓶颈问题。其次，水体中各种干扰因素较多，传感器的选择性和稳定性需要大大提高，才能增加监测的准确度。本研究创新性地结合荧光二硫化钼量子点、金纳米颗粒和适配体的各自优点，采用简单有效的内滤效应传感机制，建立了快速、灵敏和选择性测定环境中微囊藻毒素的新方法。此方法的新颖之处在于采用具有上转换荧光的二硫化钼量子点作为信号响应能够降低环境样本中的背景干扰提高探针灵敏度，以及具有高亲和力的适配体作为识别元件能够提高探针的选择性。另外，本项目探索出了可控合成荧光二硫化钼量子点的一系列方法，基于谷胱甘肽，以及牛奶等合成前体，制备出了一系列含大量氨基、羧基等功能基团的、荧光性能稳定的二硫化钼量子点，对解决目前缺乏环境友好型的、快速的二硫化钼量子点合成方法并扩展其应用范围具有一定意义。研究了适配体DNA与金纳米材料之间的相互作用力并建立其化学计量关系。本研究将所构建的光学传感探针应用于实际水样中微囊藻毒素的检测，获得了令人满意的结果。因此，此研究有助于水污染的控制和预警。