Designing Upconversion Nanocrystals Capable of 745 nm Sensitization and 803 nm Emission for Deep-Tissue Imaging
Designing Upconversion Nanocrystals Capable of 745 nm Sensitization and 803 nm Emission for Deep-Tissue Imaging
复制标题
设计能够进行 745 nm 敏化和 803 nm 发射的上转换纳米晶体，用于深层组织成像
DOI：
10.1002/chem.201602514
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发表时间：
2016-07-25
影响因子：
4.3
通讯作者：
Liu, Xiaogang
中科院分区：
文献类型：
--
作者：
Liang, Liangliang;Xie, Xiaoji;Liu, Xiaogang
本文描述了一种晶体设计策略，可以生成六边形相的NaYF4:Nd/Yb@NaYF4:Yb/Tm发光纳米晶体，该晶体在745 nm照射下能够发出803 nm的光。这是通过利用Nd3+在720和760 nm之间的大吸收截面以及通过Nd3+ -> Yb3+ -> Yb3+ -> Tm3+的高效空间能量转移和迁移来实现的。机制研究表明，一个级联的双光子能量传递上转换过程是发射机制的基础。该方案能够实现深层组织成像，同时减轻与可见光发射相关的衰减效应和传统980 nm激发所施加的过热约束。
A crystal design strategy is described that generates hexagonal-phased NaYF4:Nd/Yb@NaYF4:Yb/Tm luminescent nanocrystals with the ability to emit light at 803 nm when illuminated at 745 nm. This is accomplished by taking advantage of the large absorption cross-section of Nd3+ between 720 and 760 nm plus efficient spatial energy transfer and migration through Nd3+ -> Yb3+ -> Yb3+ -> Tm3+. Mechanistic investigations suggest that a cascaded two-photon energy transfer upconversion process underlies the emission mechanism. This protocol enables deep-tissue imaging to be achieved while mitigating the attenuation effect associated with the visible emission and the overheating constraint imposed by conventional 980 nm excitation.