单峰发射稀土上转换发光纳米材料用于小动物活体深层组织成像

Lanthanide upconversion luminescent nanomaterials have excellent value in small-animal imaging. However,common prepared lanthanide upconversion luminescent nanomaterials show multi-band emissions.The detected luminescent color will be change as the change of the injection depth when used in small-animal imaging.Thus,for small-animal deep-tissue imaging,it is meaningful to obtain lanthanide upconversion luminescent nanomaterials with intense single-band emission and high luminescent efficiency. This project aims at using thermal decomposition and hydro(solvo)thermal method followed by special surface modification to obtain monodisperse, high color purity and single-band emission of lanthanide doped upconversion luminescence nanomaterials. The suitable host materials, lanthanide ions and transition metal dopant ions will be picked out. The energy transfer mechanism between lanthanide ions or lanthanide ions and transition metal ions will be investigated. The experiment conditions for preparing lanthanide doped upconversion luminescence nanomaterials with single-band emission will be summarized. The small-animal deep-tissue imaging based on the obtained nanomaterials will be carried out. The development of this project may enrich the research content of lanthanide doped upconversion luminescence nanomaterials, expand the application area small-animal luminescent imaging based on such materials. It also may provide ideas and design methods for preparing lanthanide doped upconversion luminescence nanomaterials with single-band emission to meet the requirement of small-animal deep-tissue imaging.

稀土上转换发光纳米材料在小动物活体成像领域有着卓越的应用价值。然而，通常合成的稀土上转换发光纳米材料为多谱带发射，用于小动物活体成像时，检测到的发光颜色会随着注射深度的变化而改变。因此，实现稀土上转换发光纳米材料的高强度单峰发射上转换发光和提高上转换发光效率对于生物深层组织成像有着非常重要的意义。本项目拟采用热分解和水热溶剂热法以及特定的表面修饰方法制备单分散、高色纯度、高强度单峰发射的稀土上转换发光纳米材料。挑选出合适的基质材料、稀土离子和过渡金属离子，探究稀土离子间或稀土离子与过渡金属离子间的能量传递机制，总结合成单峰发射的稀土上转换发光纳米材料的实验条件，并且将所合成的材料用于小动物活体深层组织成像。本项目的开展有可能丰富稀土上转换发光纳米材料的研究内容，扩展该类材料在小动物活体成像的应用范围，为合成单峰发射稀土上转换发光纳米材料提供思路和设计方法，满足小动物活体深层组织成像的要求。

稀土上转换发光纳米材料由于具有较长的寿命、较低的毒性、无背景干扰和光学稳定性好等优异的物理化学特性，在小动物活体成像方面有卓越的应用价值。然而，稀土掺杂上转换发光纳米探针弱的发光强度和有限的组织穿透深度大大限制了其应用。此外，通常稀土上转换纳米材料为多谱带发射，用于活体荧光成像时检测到的荧光成像信号会随着组织深度的不同而发生变化，非常不利于活体荧光成像。本项目通过选择合适的基质材料，调节和优化掺杂离子的浓度，以及核壳结构的合理构建等，开发了一系列具有高红绿比或单峰发射特性的稀土上转换发光纳米结构，并在此基础上优化了其上转换发光性质和生物相容性，单峰上转换荧光发射最深能穿透20 mm的生物组织，在活体深层组织荧光成像方面表现出了很大的优势，同时结合计算机断层扫描成像和核磁成像，大大提高了对肿瘤组织诊断的准确性。