Bright and Stable NIR‐II J‐aggregated AIE Dibodipy for Dynamic in vivo Bioimaging

Organic dyes, emitting in the second near-infrared (NIR-II, 900-1700 nm) window, with high molar extinction coefficient (MEC) and quantum yield (QY) in aqueous is essential for in vivo bioimaging and biosensing. In this work, we developed a dibodipy based J-aggregated aggregation induced emission (AIE) molecule THPP to meet this aim. THPP exhibits a high MEC of dibodipy structure and has intensified absorption and emission in J-aggregated state, which significantly enhanced the fluorescence intensity (~55 folds) and extends the maximal absorption/emission wavelengths to 970/1010 nm in NIR-II region. Based on the bright THPP , imaging with high frame rate (34 frames per second) in a deep 'valid penetration depth' up to 6 mm can be achieved. This enabled simultaneously and dynamically imaging of vasculatures and deeply located visceral. Besides, we succeeded in monitoring the respiratory rate of acute-lung-injury mice and tracing the collateral circulation process with a high frame rate.