Fluorogenic Reactions in Chemical Biology: Seeing Chemistry in Cells.

Among the recent development of click chemistry and bioorthogonal chemistry, fluorogenic reactions occupy a unique place in that fluorescence is generated from nonfluorescent reactants, thereby rendering them highly useful and convenient in no-wash live-cell imaging. This topic was extensively reviewed in 2010 by Wang et al. (Chem. Soc. Rev.2010, 39, 1233-1239) and in 2014 by Lin et al. (Curr. Opin. Chem. Biol.2014, 21, 89-95). This review presents a comprehensive and up-to-date overview on the fluorogenic reactions in the past decade. The reactions are classified into four major categories on the basis of the mechanisms of fluorescence generation. Representative examples of each type are discussed briefly in terms of structure, mechanism, and advantages. We describe the latest applications of fluorogenic reactions in chemical biology. In the end, future opportunities and challenges in this field are tentatively proposed.