Novel NIR-II organic fluorophores for bioimaging beyond 1550 nm. Issue 10 (17th February 2020)

• Record Type: Journal Article
• Authors: Li, Yang; Liu, Yufang; Li, Qianqian; Zeng, Xiaodong; Tian, Tian; Zhou, Wenyi; Cui, Yan; Wang, Xikun; Cheng, Xiaoding; Ding, Qihang; Wang, Xiaofei; Wu, Junzhu; Deng, Hai; Li, Yanqin; Meng, Xianli; Deng, Zixin; Hong, Xuechuan; Xiao, Yuling
• Is Part Of: Chemical science. Volume 11:Issue 10(2020)
• Page Start: 2621
• Page End: 2626
• Publication Date: 2020-02-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c9sc06567a
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Novel NIR-II organic fluorophores were designed and synthesized using an AIE and highly twisted donor–acceptor distortion strategy for bio-imaging beyond 1550 nm. Abstract : Near-infrared fluorescence imaging in the 1500–1700 nm sub-window (NIR-IIb) has shown a deeper penetration depth, higher resolution and zero auto-fluorescence for biomedical imaging. Till now, very few small molecule NIR-IIb fluorophores have been reported due to the extremely rare organic NIR-IIb skeleton and a notorious aggregation-caused quenching (ACQ) effect in aqueous solution. In this study, highly twisted NIR-II small molecule fluorophores such as HL3 (45.5° at the S0 state) with the emission wavelength extending into the NIR-IIb region were designed and synthesized using an aggregation-induced emission (AIE) strategy. HL3 dots showed a remarkable increase in fluorescence intensity with a QY of 11.7% in the NIR-II window (>1000 nm) and 0.05% in the NIR-IIb region (>1550 nm) in water. High-resolution in vivo imaging of the whole body, cerebral vasculature, and lymphatic drainage beyond 1550 nm was achieved using NIR-II AIE HL3 dots for the first time. These attractive results may promote the development of small-molecule NIR-IIb fluorophores with the maximum emission wavelength beyond 1500 nm with a deeper penetration depth and higher resolution.