Incorporation of Planar Blocks into Twisted Skeletons: Boosting Brightness of Fluorophores for Bioimaging beyond 1500 Nanometer

• DOI: 10.1021/acsnano.0c07527
• Publication Date: 2020-10-01T18:08:09Z
• Authors: Shunjie Liu; Runze Chen; Jianquan Zhang; Yuanyuan Li; Mubin He; Xiaoxiao Fan; Haoke Zhang; Xuefeng Lu; Ryan T. K. Kwok; Hui Lin; Jacky W. Y. Lam; Jun Qian; Ben Zhong Tang
• Keywords: Quantum yield

The brightness of organic fluorescence materials determines their resolution and sensitivity in display detection. However, strategies to effectively enhance the are still scarce. Conventional planar π-conjugated molecules excellent photophysical properties as isolated species but suffer from aggregation-caused quenching effect when aggregated owing cofacial π–π interactions. In contrast, twisted show high photoluminescence quantum yield (ΦPL) aggregate while at cost absorption due breakage conjugation. Therefore, it is challenging integrate strong solid-state ΦPL, which two main indicators brightness, into one molecule. Herein, we propose a molecular design strategy boost through incorporation blocks skeletons. As proof-of-concept, small-molecule TT3-oCB with larger dithieno[3,2-b:2′,3′-d]thiophene unit displays superb NIR-IIb (1500–1700 nm) than that TT1-oCB TT2-oCB smaller thiophene thienothiophene unit, respectively. Whole-body angiography using nanoparticles presents an apparent vessel width 0.29 mm. Improved image achieved for femoral vessels only 0.04 High-magnification through-skull microscopic imaging cerebral vasculature gives ∼3.3 μm. Moreover, deeply located internal organ such bladder identified clarity. present philosophy embodies platform further development vivo bioimaging.