基于活性磷原位检测的MOFs纳米捕获材料合成及荧光增强机制研究

The excessive level of labile phosphorus is one of the most important factors causing the eutrophication of water bodies. However, the existing analytical strategies cannot meet the requirements for in-situ online sequestrating and onsite detection of water quality. Faced with the issues mentioned above, metal-organic frameworks (MOFs) (i.e. (Eu, Zr)-MOFs and UiO-66-NH2, etc.) nano capturing materials will be synthesized for the selective detection through the modulation of organic complexes and metal ions. The relationship among composition, structure, surface modification and sensing mechanism will be investigated in detail. At the same time, the physical and chemical behavior, the corresponding selective sensing mechanism caused by the interaction between MOFs and labile phosphorus will be also studied. The detection method for labile phosphorus based on fluorescence enhanced mechanism of MOFs nano capturing materials is established according to the relationship between the microstructure and sensing properties of MOFs nano capturing materials. In view of the preferable affinity for labile phosphorus of MOFs nano capturing materials, in-situ accumulation for labile phosphorus based on diffusive gradients in thin-films technique (DGT), and the integrated effects, the in-situ sensitive detection for labile phosphorus in the field of aquatic environment will be achieved through the optimization of MOFs nano capturing materials and diffusion thin film. The original innovativeness will be realized by the successful implement of the present project at different levels, including novel nanostructured materials, new detective principles and mechanism, which lays the solid foundation for the monitoring of water quality security and early-warning of eutrophication occurrence.

活性磷含量超标是造成水体富营养化的主要因素之一，然而现有的检测技术不能满足野外水质信息原位在线收集与现场检测的需求。针对上述问题，本课题拟通过筛选合适的有机配体与金属中心，设计合成对活性磷具有选择性识别功能的金属有机框架（MOFs）纳米捕获材料（如(Eu,Zr)-MOFs、UiO-66-NH2等）；系统研究组成、结构、功能化修饰与传感机制之间的内在关联，揭示其与活性磷相互作用的物理化学行为及诱导产生选择性响应的微观机制；梳理微观结构与敏感性能之间的关系，研发基于荧光增强原理的活性磷检测关键技术；优化MOFs纳米捕获材料与扩散控制膜的匹配性，利用MOFs纳米捕获材料的选择性识别、薄膜梯度扩散技术（DGT）的原位富集以及二者的协同效应实现野外水体环境中活性磷的原位在线检测。本项目的实施将在新材料体系、新型检测机制与技术等层面实现创新，并对判断水体的营养化程度、提升环境预警能力发挥重大作用。

本项目严格按照任务书要求，围绕水源系统中活性磷与重金属原位、在线检测的实用化目标，从功能纳米材料的设计制备、微观结构调控、荧光增强机理、新型DGT荧光传感器等几个层面开展相应的基础科学研究。主要研究内容如下：（1）针对水体富营养化问题，制备了尺寸可调的锆基金属有机骨架材料（UiO-66），探究了其对磷酸盐的吸附性能及吸附机理；（2）以纳米颗粒为薄膜梯度扩散技术（DGT）捕获相，发展了基于锆基金属有机框架材料（UiO-66）的原位水体中活性磷检测技术，利用MOFs纳米捕获材料的选择性识别、DGT的原位富集以及二者的协同效应实现了野外水体环境中活性磷的原位在线检测；（3）合成了双功能配位聚合物NH2-MIL-88(Fe)，实现了对水体中As(V)的基于荧光增强原理的选择性、高灵敏度检测检测和有效去除；（4）设计了了UiO-66(Zr)/泡沫碳块体复合材料，应用于含氟污水修复；（5）针对砷污染，制备了形貌可控的双金属有机骨架材料（Fe/Mg-MIL-88B），探究了其对水体中As(V)的选择性去除及机理；（6）针对重金属污染，制备了铝基金属有机骨架材料（NH2-MIL-53）/木炭复合膜（NH2-MIL-53/WC）、MoS42-功能化的三维分级结构NiFe-LDH/泡沫碳复合材料以及分级孔Fe-MOG/BC气凝胶，研究了其对重金属的吸附性能以及吸附机理。本项目共发表SCI论文19篇，其中1区16篇；申请发明专利10项，授权发明专利3项。本项目的实施在新材料体系、新型检测机制、富集与检测的集成等多个层面实现创新，并对判断水体的营养化程度、提升环境预警能力发挥重大作用；为建立针对水体环境中目标重金属离子的高效、稳定、选择性富集与超灵敏探测的一体化分析奠定基础。