Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
J Am Chem Soc. 2013 Aug 28;135(34):12608-11. doi: 10.1021/ja4075002. Epub 2013 Aug 19.
A new type of core-shell upconversion nanoparticles which can be effectively excited at 795 nm has been designed and synthesized through spatially confined doping of neodymium (Nd(3+)) ions. The use of Nd(3+) ions as sensitizers facilitates the energy transfer and photon upconversion of a series of lanthanide activators (Er(3+), Tm(3+), and Ho(3+)) at a biocompatible excitation wavelength (795 nm) and also significantly minimizes the overheating problem associated with conventional 980 nm excitation. Importantly, the core-shell design enabled high-concentration doping of Nd(3+) (~0 mol %) in the shell layer and thus markedly enhanced the upconversion emission from the activators, providing highly attractive luminescent biomarkers for bioimaging without autofluorescence and concern of overheating.
一种新型的核壳上转换纳米粒子，通过空间限制掺杂钕（Nd(3+)）离子，可在 795nm 处有效激发。使用 Nd(3+)离子作为敏化剂，可促进一系列镧系元素激活剂（Er(3+)、Tm(3+)和 Ho(3+)）在生物相容性激发波长（795nm）处的能量转移和光子上转换，同时显著减少与传统 980nm 激发相关的过热问题。重要的是，核壳设计允许在壳层中高浓度掺杂 Nd(3+)（约 0mol%），从而显著增强了激活剂的上转换发射，提供了高吸引力的生物成像荧光生物标志物，没有自发荧光和过热的担忧。
