基于上转换材料和选择性载体的光学传感器的研究和应用

The project will study the development and applications of upcoverting material based polymeric optodes for ions and neutral analytes. Due to its high sensitivity，fluorescence measurement has been extensively used in the analysis of biological samples in clinical analysis and biomedical research. However, ion optodes based on traditional chromoionophores cannot be utilized on whole blood measurements because of the strong background absorption, significant autofluorescence, and scatter observed from blood in the UV and visible region.Among numerous fluorescent dyes, upconverting nanomaterials exhibit unique properties, that is the emission at visible and NIR wavelengths when excited with 980 nm laser source. The large anti-stokes shift allows easy separation of the discrete emission peaks from the excitation source. The background absorption and sample autofluorescence are greatly reduced that leads to highly sensitive optical measurement. Unlike conventional organic dyes or quantum dots, upconverting nanoparticles exhibit neither photoblinking on the millisecond and second time scales nor photobleaching even with hours of continuous excitation, and their cytotoxicity is very low, thus have been successfully used in small animals imaging even cell imaging. NaYF4 has been shown to be the most efficient host material for upconverting nanocrystals among various materials. By combining the nanomaterials with suitable recognition indicators, we can design upconverting optical sensors based on Inner Filter effect and FRET mechanisiums. which makes the inert nanorods ion-sensitive. Optodes for pH, electrolytes (Na+, K+, Ca2+ and Cl-) and small molecules(glucose,et al.)will be prepared, characterized and applied in direct fluorescent measurement in whole blood and cell.

本项目创新性的提出基于上转换材料和选择性探针的高分子光学传感器的研究和应用，通过内滤体系和共振能量转移体系建立上转换荧光对被测物响应的机制，系统研究上转换材料在高分子传感膜中的性能以及和其它传感材料之间的相互作用和影响，通过使用疏水性高分子传感材料分散纳米颗粒并制备传感器件，解决上转换材料的尺度、形态和发光效率之间的矛盾，避开水溶性上转换材料的复杂制备过程，解决目前该领域中存在的问题和难点，在材料合成、器件制备和条件优化等等方面有所突破，并将这种技术应用到生物样品分析等领域，弥补传统光学检测和紫外激发荧光分析方法的不足，实现对复杂样品灵敏、快速、准确、无损的检测和原位分析。

本项目按计划执行情况良好，成功完成了多方面的研究工作。依照项目计划，选择并成功制备对于上转换镧系离子最好的主体材料之一的NaYF4体系，研究了不同尺度、形状和表面修饰的NaYF4纳米材料，通过固定在疏水性高分子传感膜体系中，使发光材料保持高量子产率和发光效率，解决了在水溶液中上转换材料发光效率低的问题。成功设计制备了可以和上转换材料组成能量共振体系的小分子近红外探针，将该体系成功应用于生物样品和细胞检测分析。本项目研究成果发表SCI论文9篇。