纳米晶体自组装结构中非辐射能量传递过程的验证

以上转换纳米粒子NaYF₄：20% Yb，2% Er@NaYF₄（标记为UCNP）和金纳米粒子（AuNP）分别作为能量传递研究的给体和受体，研究在具有确定位置关系的组装结构中二者之间的非辐射能量传递是否存在。以UCNP和AuNP作为基本构建单元，采用气-液界面溶剂挥发法，得到了连续大面积规整排列的二维UCNP单层自组装膜。再通过层层组装得到UCNP+AuNP双层膜、UCNP+NaYF₄+AuNP三层膜。利用自行搭建的光谱成像系统对自组装结构进行了发光性质测试。对比3种膜结构的发光情况，发现UCNP+AuNP双层膜和UCNP+NaYF₄+AuNP三层膜的发光与UCNP单层膜减弱幅度相近，即在我们研究的体系中UCNP和AuNP之间不存在明显的非辐射能量传递过程。本研究提供了一种几何关系明确的组装体模型，并搭建了相应的微区发光性质测试设备，验证了在我们设计的自组装模型中并不存在UCNP与AuNP的非辐射能量传递。

Checking of Non-radiative Energy Transfer Process in Nanocrystal Self-Assembly Structure

Upconversion nanoparticles NaYF₄:20%Yb, 2%Er@NaYF₄ (marked as UCNP) and gold nanoparticles (AuNP) were used as donors and acceptors to study non-radiative energy transfer in an assembly structure with a defined position relationship. Using UCNP and AuNP as basic building units, two-dimensional UCNP monolayer with large area and regular arrangement were self-assembled by solvent evaporation method at liquid-air interface. UCNP+AuNP bilayer and UCNP+NaYF₄+AuNP trilayer structures were prepared by layer-by-layer assembly. Then the luminescent properties of self-assembled films were characterized by the spectral imager system which was designed by our group. The spectrum of three kinds of films were compared. It was found that the luminescence attenuation of UCNP+AuNP bilayer structure and UCNP+NaYF₄+AuNP trilayer structure were similar, compared with UCNP monolayer. That is, there is no obvious non-radiative energy transfer between UCNP and AuNP in our research system. In the research, a well-geometric assembly model was provided, and the luminescence test equipment was set up, and it was verified that there was no non-radiative energy transfer between UCNP and AuNP in our self-assembly models.