A dual-emission fluorescent probe for simultaneous detection of singlet oxygen and hypochlorous acid in lipid droplets

Singlet oxygen (1O2) and hypochlorite (ClO-) are two important reactive oxygen species. They coexist in living systems and can be interconverted in organisms, being involved in a variety of pathophysiological processes. Lipid droplets (LDs) are organelles that transport and store lipids, and 1O2 and ClO- tend to destroy unsaturated lipids, leading to lipid oxidation and causing a range of diseases. Here we proposed the first dual-response fluorescent probe DBCC that can simultaneously distinguish 1O2 and ClO- within LDs. The probe is almost non-fluorescent, while significant fluorescence enhancement can be observed in the blue and green channels after treatment with 1O2 and ClO-, respectively. With the excellent properties of high sensitivity, good selectivity and wide tolerance range, the probe DBCC has been successfully used to detect 1O2 and ClO- in HepG2 cells and zebrafish, and faultlessly realized endogenous and exogenous 1O2 and ClO- imaging in LDs. This work provides a powerful analytical tool for further investigating the levels of 1O2 and ClO- in LDs and associated diseases.