An acetylpyrene-based fluorescent probe for selective detection of cysteine in vitro and in lipid droplets

Abstract

The development of organelle-targeted probes that enable specific recognition and detection Cysteine (Cys) may provide an effective way to explore physiological processes and pathological mechanisms associated with the related diseases. In this work, an acetylpyrene-based fluorescent probe CP-1 was designed and synthesized for detecting Cys in vitro and in vivo. The probe exhibited a noticeable fluorescence blue shift upon the addition of Cys under UV light, attributed to the mechanism of the nucleophilic addition reaction. The response mechanism for Cys was studied by time-dependent density functional theory (TD-DFT) calculations and mass spectra (MS). CP-1 can not only specifically recognize Cys in the presence of other amino acids and biothiols, but also exhibit the property of targeting lipid droplets (LDs). Due to the good cell biocompatibility, CP-1 has been successfully employed for real-time tracking Cys in LDs of living cells. The ability to target LDs and the favorable biocompatibility make the probe valuable for investigating Cys-related diseases in living cell systems.