Simultaneously Achieving Lipid-Droplet-Location and Activity-Based Fluorogenic Sensing of Hydrogen Peroxide by Dicyanofuran-Fused Coumarin Derivatives

Activity-based sensing of hydrogen peroxide (H₂O₂) in specific organelles of interest is significant for deciphering its physiological functions at the subcellular level. However, currently reported H₂O₂-responsive moieties lack organelle targetability, necessitating an auxiliary navigation to direct the probe molecule to the targeted cellular local region. Herein, we propose an economical strategy by integrating a dual-functional moiety that combines molecular recognition and organelle targeting. By exploiting the oxidation reaction of dicyanofuran, two novel H₂O₂-activatable probes capable of targeting lipid droplets (LDs) were rationally designed based on the coumarin scaffold. Notably, the dicyanofuran-fused coumarin derivative FC1 could effectively image endogenous and exogenous H₂O₂ in LDs of living cells and has been successfully utilized to distinguish cancer cells from normal cells by leveraging the synergistic combination of elevated H₂O₂ levels and LD abundance. Our work not only presents a new activity-based sensing mechanism for H₂O₂ but also provides a versatile approach for the development of subcellular fluorescent probes in the future.