Harnessing a multifunctional far-red fluorescence platform for high-performance biological sensing and imaging

Fluorescence imaging has provided abundant information in biological researches, which unveils the microscopic nexuses in physiological and pathological processes. Nevertheless, this main-stream solution is always impeded by intractable drawbacks of imaging tools including small Stokes shift, short-wavelength emission, inferior photostability, and insufficient fluorescence quantum yield (Φ_F). In this contribution, an ingenious molecular platform constituted of three novel dicyanocoumarin analogues is rationally engineered. With large Stokes shift, its fluorescence is located in the far-red region. Serendipitously, an unexpected phenomenon is uncovered that emission of these novel compounds enhances along with the increase of polarity, which confers them considerable Φ_F. Due to such merits, this multifunctional fluorescence platform is applied to cellular imaging due to its multivariate spectral responsiveness toward pH, polarity, and hypochlorous acid (HClO). Besides, in vivo imaging of ferroptosis and wound inflammation mouse models has also revealed the great potential of this fluorescence platform. Performing eminent bioimaging results, we conceive that this fluorescence platform would be a robust imaging toolbox in the future, which provides designing inspiration for development of high-performance fluorophores.