Developing Long Lifetime Quinacridone Derivative for Fluorescence Lifetime Imaging of Living Cells

Fluorescence lifetime imaging has become increasingly popular in bioimaging analysis, owing to its distinct advantages. It is independent of probe concentration and excitation power, effectively avoids autofluorescence interference in organisms, and can distinguish between spectrally similar fluorophores. In this study, we developed CMFL-Chol, a polarity-sensitive thermally activated delayed fluorescence (TADF) material with a quinacridone fluorophore core. The fluorescence lifetime of CMFL-Chol is 16.70 ns. To enhance its water solubility, we encapsulated CMFL-Chol using DSPE-PEG-MAL, synthesizing CMFL-Chol nanoparticles (NPs) with a fluorescence lifetime of 13.11 ns. Finally, we applied CMFL-Chol NPs to fluorescence lifetime imaging in cells. The results demonstrated that CMFL-Chol NPs hold great potential for analyzing cellular physiological activity processes.