纳米纤维比率荧光探针可视化检测水胺硫磷的研究

The residual organic pesticide in agricultural products has severely impair on the health of human consumers. Currently, the most used methods for detecting residual pesticide in agricultural products are chromatography and/or Immunoassay, which usually needs a time-consuming and complicated procedure. Therefore, it is essential to develop the more rapidly and effective method for detection of organic pesticide. This project is aiming to fabricate a novel ratiometric fluorescence probe with nanofibrous structure for the instant visual detection of Isocarbophos. The probe is consisted with fluorescent dyes encapsulated in polymeric nanofibers served as the fluorescence interior label, and the Quantum Dots (QDs) assembled on the surface of nanofibers, respectively. Semiconductor QDs, also known as nanocrystals or quasi zero dimensional materials, have gained a center stage of interest both in fundamental and industrial areas as a consequence of the unique optical and electronic properties. QDs show great promise in molecular detection through outputting corresponding fluorescence signal by the Fluorescence resonance energy transfer (FRET). The nanofibrous ratiometric fluorescence probe comprised “Fluorescent Dye-QDs Hybrid (FDQH)” provides a new concept and utility for visual detection of hazardous substance in various conditions. The fluorescence of red dye in the nanofibers stays constant, whereas the green QDs on the surface of nanofibers bind Isocarbophos, leading to the green fluorescence quenching due to the FRET effect. The variations of the two fluorescence intensity ratios display continuous color changes from green to red upon exposure to different amounts of Isocarbophos. The change of fluorescent color generates chromatic aberration which can be detected and visible to naked eyes. In this project, the physicochemical properties of nanofibrous ratiometric fluorescence probe are investigated for illuminating the effect laws of nanofibers structure on the fluorescence properties of probe. Furthermore, the foundational principles of visible detecting Isocarbophos is investigated. This project is also promised to provide practice foundations and theoretical basis for developing novel techniques of fluorescence probe.

残留于农产品中的有机农药严重危害消费者的身体健康。目前，用于检测农产品上残留农药的色谱法和免疫分析法存在着检测过程繁琐、耗时耗力等缺陷；因此，亟需开发更加快速、有效的检测方法。本项目拟制备具有纳米纤维结构的比率荧光探针，用于农药水胺硫磷的可视化检测。该探针由包覆于纳米纤维芯层的红色荧光染料和组装于纳米纤维表面的绿色量子点构成。纳米纤维超大的比表面积能够吸附和富集水胺硫磷，使位于纳米纤维表面的量子点猝灭而产生荧光强度的减弱，同时位于纤维芯层的染料荧光强度不变，从而产生肉眼可见的颜色差，实现可视化检测水胺硫磷的目的。通过研究纳米纤维比率荧光探针的组成与物理化学性能，阐明纳米纤维结构对探针荧光性能的影响规律，以及纳米纤维比率荧光探针可视化检测水胺硫磷的基本原理，为开发新型的荧光探针技术提供实践基础和理论依据。

本课题聚焦于制备纳米纤维结构的比率荧光探针，并应用于有害化学物，如水胺硫磷、氯霉素等的可视化检测。通过将荧光发光物质与纳米纤维复合，其中，荧光发光物质与成纤材料共混纺丝得到具有背景颜色的纳米纤维，而后在纳米纤维表面组装可与被测物反应从而猝灭的量子点。该量子点的颜色与荧光背景的颜色相异并强于背景荧光物质。当被测物与量子点结合后可猝灭量子点荧光发光，使得背景色显现，从而实现有害物质的可视化检测。.基于以上阐述，本课题在实施期间，主要进行了以下工作：.1）量子点纤维复合物的制备，在纤维上复合量子点，构建功能荧光纤维或纳米纤维用于有害小分子的检测；. 通过水热法，采用尿素和柠檬酸为原料，以入十六烷基三甲基溴化铵和三丁基磷酸为活性剂，在经氢氧化钠溶液活化预处理的棉纤维中原位制备量子点，得到了具有荧光发射效应的碳量子点棉纤维；另外，通过乳液静电纺丝方法在聚乳酸纤维中复合量子点，并将其应用于氯霉素的检测。.2）比率荧光探针的构建；包括作为背景颜色使用的无机荧光发光物质及其复合纤维的制备和性能研究；复合量子点的纳米纤维的制备及其对模型分子的检测性能；以及比率荧光纳米纤维的制备及其对模型分子的可视化检测；.采用微波辅助化学共沉淀法(MA-CCP)制备掺杂Eu2+和Nd3+的CaAl2O4荧光粉样品，以作为后续比率荧光探针的底色物质，并对所制备的荧光样品进行了结构和光致发光性能的研究。.制备不同颜色的荧光无机物，通过比例调整得到了发射白色光的荧光复合物，并采用溶液纺丝方法制备得到了热致变色的聚丙烯腈纤维，检测了其物理化学性能以及热致变色性能。结果表明该纤维能够通过肉眼检测到环境温度的响应变化。.在开发背景荧光无机物和量子点的基础上，将两者复合，得到了比率荧光纳米纤维复合探针，并将其应用在水胺硫磷的可视化检测。.3）光催化降解的相关研究，以去除体系中的有害小分子。.在完成可视化检测探针的基础上，开发出具有光催化降解效应的纳米纤维复合物，用于去除体系中有害小分子。