Chemical Research in Chinese Universities ›› 2021, Vol. 37 ›› Issue (4): 943-950.doi: 10.1007/s40242-021-1172-9

• Articles • Previous Articles     Next Articles

Rare-earth Doped Nanoparticles with Narrow NIR-II Emission for Optical Imaging with Reduced Autofluorescence

LU Feng1, ZHAO Ting1, SUN Xiaojun1, WANG Zuqiang1, FAN Quli1, HUANG Wei1,2   

  1. 1. State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials(IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, P. R. China;
    2. Frontiers Science Center for Flexible Electronics(FSCFE), MIIT Key Laboratory of Flexible Electronics(KLoFE), Northwestern Polytechnical University, Xi'an 710072, P. R. China
  • Received:2021-04-14 Revised:2021-05-22 Online:2021-08-01 Published:2021-06-09
  • Contact: FAN Quli E-mail:iamqlfan@njupt.edu.cn
  • Supported by:
    This work was supported by the National Natural Science Foundation of China(Nos.21975131, 21674048), the Fund of Synergetic Innovation Center for Organic Electronics and Information Displays, and the Primary Research & Development Plan of Jiangsu Province, China(No.BE2016770).

Abstract: Fluorescence imaging in the second near-infrared region(900-1700 nm, NIR-II) with a high resolution and penetration depth due to the significantly reduced tissue scattering and autofluorescence has emerged as a useful tool in biomedical fields. Recently, many efforts have been devoted to the development of fluorophores with an emission band covering the long-wavelength end of NIR-II region(1500-1700 nm) to eliminate the autofluorescence. Alternatively, we believe imaging with a narrow bandwidth could also reduce the autofluorescence. As a proof of concept, NaYF4:Yb,Nd@NaYF4 downconversion nanoparticles(DCNPs) with sharp NIR-II emission were synthesized. The luminescence of DCNPs showed a half-peak width of 49 nm centered at 998 nm, which was perfectly matched with a (1000±25) nm bandpass filter. With this filter, we were able to retain most of the emissions from the nanoparticles, while the autofluorescence was largely reduced. After PEGylation, the DCNPs exhibited great performance for blood vessel and tumor imaging in living mice with significantly reduced autofluorescence and interference signals. This work provided an alternative way for the low-autofluorescence imaging and emphasized the importance of narrow emitting rare-earth doped nanoparticles for NIR-II imaging.

Key words: Second near-infrared, Rare-earth, Downconversion nanoparticle, Autofluorescence, Fluorescence imaging