Highly luminescent, biocompatible ytterbium(iii) complexes as near-infrared fluorophores for living cell imaging

Yingying Ning; Juan Tang; Yi-Wei Liu; Jing Jing; Yuansheng Sun; Jun-Long Zhang

doi:10.1039/c8sc00259b

Highly luminescent, biocompatible ytterbium(iii) complexes as near-infrared fluorophores for living cell imaging

Chem Sci. 2018 Mar 19;9(15):3742-3753. doi: 10.1039/c8sc00259b. eCollection 2018 Apr 21.

Authors

Yingying Ning¹, Juan Tang¹, Yi-Wei Liu¹, Jing Jing², Yuansheng Sun³, Jun-Long Zhang¹

Affiliations

¹ Beijing National Laboratory for Molecular Sciences , State Key Laboratory of Rare Earth Materials Chemistry and Applications , College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , P. R. China . Email: zhangjunlong@pku.edu.cn.
² School of Chemistry , Beijing Institute of Technology , Beijing 100081 , P. R. China.
³ ISS Inc , Champaign , IL 61822 , USA.

Abstract

Herein, we report the design and synthesis of biocompatible Yb³⁺ complexes for near-infrared (NIR) living cell imaging. Upon excitation at either the visible (Soret band) or red region (Q band), these β-fluorinated Yb³⁺ complexes display high NIR luminescence (quantum yields up to 23% and 13% in dimethyl sulfoxide and water, respectively) and have higher stabilities and prolonged decay lifetimes (up to 249 μs) compared to the β-non-fluorinated counterparts. This renders the β-fluorinated Yb³⁺ complexes as a new class of biological optical probes in both steady-state imaging and time-resolved fluorescence lifetime imaging (FLIM). NIR confocal fluorescence images showed strong and specific intracellular Yb³⁺ luminescence signals when the biocompatible Yb³⁺ complexes were uptaken into the living cells. Importantly, FLIM measurements showed an intracellular lifetime distribution between 100 and 200 μs, allowing an effective discrimination from cell autofluorescence, and afforded high signal-to-noise ratios as firstly demonstrated in the NIR region. These results demonstrated the prospects of NIR lanthanide complexes as biological probes for NIR steady-state fluorescence and time-resolved fluorescence lifetime imaging.