Er3+ self-sensitized nanoprobes with enhanced 1525 nm downshifting emission for NIR-IIb in vivo bio-imaging. Issue 12 (16th March 2021)

• Record Type: Journal Article
• Authors: Wang, Wang; Feng, Zhe; Li, Bai; Chang, Yulei; Li, Xu; Yan, Xu; Chen, Runze; Yu, Xiaoming; Zhao, Huiying; Lu, Geyu; Kong, Xianggui; Qian, Jun; Liu, Xiaomin
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 12(2021)
• Page Start: 2899
• Page End: 2908
• Publication Date: 2021-03-16
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Biomedical materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tb02728f
• Languages: English
• ISSNs: 2050-750X

Abstract

Abstract : An efficient NIR-IIb nanoprobe was designed with the 1525 nm QY of 13.92% for cerebrovascular microscopy imaging and various physiological dynamic imaging. Abstract : Traditional sensitizer (Yb 3+ or Nd 3+ ) and activator (Er 3+ ) co-doped lanthanide-based nanoprobes possessing emission of Er 3+ at 1525 nm have attracted much attention in NIR-IIb bio-imaging. However, the 1525 nm fluorescence efficiency was not high enough in such co-doped systems due to the serious back energy transfer from the activator to the sensitizer, resulting in a lot of excitation energy loss. Herein, we have designed an efficient NIR-IIb nanoprobe Er 3+ self-sensitized NaErF4 :0.5%Tm 3+ @NaLuF4, where substantially all the excitation energy could contribute to Er 3+ ions and most energy transfer processes were confined among Er 3+ ions, avoiding the energy dissipation by heterogeneous sensitizer ions. The influence of the types of epitaxial heterogeneous shells, the doping effect and optimal doping concentration of Tm 3+ ions, as well as the critical shell thickness for obtaining the surface quenching-assisted downshifting emission are systematically investigated to acquire the most efficient 1525 nm luminescence under 800 nm excitation. The quantum yield in the 1500–1700 nm region reached 13.92%, enabling high-resolution through-skull cerebrovascular microscopy imaging and large-depth in vivo physiological dynamic imaging with an extremely low excitation powder density of 35 mW cm −2 . The designed nanoprobe can be potentially used for brain science research and clinical diagnosis.