A General Strategy Toward Highly Fluorogenic Bioprobes Emitting across the Visible Spectrum.

A general approach toward highly fluorogenic probes across the visible spectrum for various analytes offers significant potential for engineering a wide range of bioprobes with diverse sensing and imaging functions. Here we show a facile and general strategy that involves introducing a new fluorogenic mechanism in boron dipyrromethene (BODIPY) dyes, based on the principle of stimuli-triggered dramatic reduction in the electron-withdrawing capabilities of the meso-substituents of BODIPYs. The fluorogenic mechanism has been demonstrated to be applicable in various BODIPYs with emission maxima ranging from green to far red (509, 585, and 660 nm), and the synthetic strategy allows access to a panel of highly fluorogenic bioprobes for various biomolecules and enzymes (H2O2, H2S, and protease) via introducing specific triggering motifs. The potency of the general design strategy is exemplified by its application to develop a mitochondria-targeting far-red probe capable of imaging of endogenous H2O2 in living cells.