writer：Benzhao He, Li Zhou*, Jiachang Huang
keywords：Luminescence，Nanoparticles，Upconversion，Water-dispersible，Functional
source：期刊
specific source：Mater. Lett. 2014, 117, 142-145
Issue time：2014年

Rare-earth upconversion nanophosphors (UCNPs) with high water-dispersibility and surface functional groups are promising for bioimaging. In this paper, we reported a facile strategy for one-step synthesis of water-dispersible hydroxyl-functionalized NaYF₄:Yb/Er UCNPs based on the solvothermal technique by using ricinoleic acid as ligand. TEM and XRD characterizations indicate that the synthesized UCNPs possess hexagonal phase structure and spherical shape with a mean diameter of 20 nm. The UCNPs show excellent water-dispersibility and strong upconversion luminescence. Moreover, the presence of hydroxyl groups on the surface of NaYF₄:Yb/Er allows for further modification as confirmed by the successful reaction with dodecanoyl chloride. Our strategy opens up opportunities to make full use of water-dispersible UCNPs in various applications because of their facile availability, cost-effective productivity and favorable surface functionality.