Song Nan, Zhou Bo, Yan Long, Huang Jinshu, Zhang Qinyuan
State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, Institute of Optical Communication Materials, South China University of Technology, Guangzhou, China.
Front Chem. 2019 Jan 25;6:673. doi: 10.3389/fchem.2018.00673. eCollection 2018.
The realization of upconversion at 808 nm excitation has shown great advantages in advancing the broad bioapplications of lanthanide-doped nanomaterials. In an 808 nm responsive system, Nd and Yb are both needed where Nd acts as a sensitizer through absorbing the excitation irradiation. However, few studies have been dedicated to the role of Yb. Here, we report a systemic investigation on the role of Yb by designing a set of core-shell-based nanostructures. We find that energy migration over the ytterbium sublattice plays a key role in facilitating the energy transportation, and moreover, we show that the interfacial energy transfer occurring at the core-shell interface also has a contribution to the upconversion. By optimizing the dopant concentration and surface anchoring the infrared indocyanine green dye, the 808 nm responsive upconversion is markedly enhanced. These results present an in-depth understanding of the fundamental interactions among lanthanides, and more importantly, they offer new possibilities to tune and control the upconversion of lanthanide-based luminescent materials.
在808nm激发下实现上转换在推动镧系掺杂纳米材料广泛的生物应用方面展现出了巨大优势。在一个808nm响应体系中，钕（Nd）和镱（Yb）都是必需的，其中Nd通过吸收激发辐射充当敏化剂。然而，很少有研究关注Yb的作用。在此，我们通过设计一组基于核壳的纳米结构，对Yb的作用进行了系统研究。我们发现镱亚晶格上的能量迁移在促进能量传输方面起着关键作用，此外，我们还表明在核壳界面发生的界面能量转移对上转换也有贡献。通过优化掺杂剂浓度并在表面锚定红外吲哚菁绿染料，808nm响应的上转换得到了显著增强。这些结果深入理解了镧系元素之间的基本相互作用，更重要的是，它们为调节和控制镧系发光材料的上转换提供了新的可能性。
