Indole-substituted flavonol-based cysteine fluorescence sensing and subsequent precisely controlled linear CO liberation

, simultaneously serving as a precursor of photoCORM, actuated by Cys and triggered by visible light, releasing linear CO in aerobic environments. This work not only provides promising applications for the detection and visualization of exogenous and endogenous Cys, and spatiotemporally controllable CO liberation in live systems, but will also facilitate the development of handy molecular tools for clinical diagnosis and CO gas therapy.