Rare‐Earth Nanoparticles with Enhanced Upconversion Emission and Suppressed Rare‐Earth‐Ion Leakage

• DOI: 10.1002/chem.201103485
• Publication Date: 2012-04-04T19:53:23Z
• Authors: Ye‐Fu Wang; Ling‐Dong Sun; Jia‐Wen Xiao; Wei Feng; Jia‐Cai Zhou; Jie Shen; Chun‐Hua Yan
• Keywords: Ions; Luminescent Agents; Microscopy, Confocal; Luminescent Measurements; Humans; Nanoparticles; Metals, Rare Earth; 02 engineering and technology; Particle Size; 0210 nano-technology; 01 natural sciences; HeLa Cells; 0104 chemical sciences

AbstractUpconversion emissions from rare‐earth nanoparticles have attracted much interest as potential biolabels, for which small particle size and high emission intensity are both desired. Herein we report a facile way to achieve NaYF4:Yb,Er@CaF2 nanoparticles (NPs) with a small size (10–13 nm) and highly enhanced (ca. 300 times) upconversion emission compared with the pristine NPs. The CaF2 shell protects the rare‐earth ions from leaking, when the nanoparticles are exposed to buffer solution, and ensures biological safety for the potential bioprobe applications. With the upconversion emission from NaYF4:Yb,Er@CaF2 NPs, HeLa cells were imaged with low background interference.