Polarity-Sensitive Ratiometric Fluorescence Probe for Monitoring Lipid Droplets/Nucleus Change During Ferroptosis.

Ferroptosis regulates cell death through reactive oxygen species associated lipid peroxide accumulation, which is expected to affect the structure and polarity of lipid droplets (LDs), but with no clear evidence. Herein, we report the first example of LD and nucleus dual-targeted ratiometric fluorescent probe of CQPP for monitoring polarity change in cellular microenvironment. Due to the appropriate donor-acceptor structure of CQPP, it offers ratiometric fluorescence emission and fluorescence lifetime signals to polarity variations. Using nucleus imaging as a reference, CQPP has been successfully applied to report the increase in LD polarity, the homogenization of polarity in LDs and cytoplasm in the ferroptosis model. This LD and nucleus dual-targeted fluorescent probe shows great potential of using fluorescence imaging to study ferroptosis and ferroptosis-related diseases.