Lipid droplets-specific fluorescent probe for wash-free imaging and in vivo diagnosis of non-alcoholic fatty liver disease.

Lipid droplets (LDs) dysfunction is closely associated with a multitude of diseases, including nonalcoholic fatty liver disease (NAFLD). Therefore, it is imperative to develop fluorescent probes that specifically target LDs for the early detection and diagnosis of NAFLD. In this study, a series of lipophilic fluorophores CZ1-CZ4 that feature a D-π-A configuration were designed and synthesized based on the carbazole and tricocyanofuran derivatives. The photophysical data revealed that all four probes exhibited large Stokes shifts (~ 120 nm) in high-polarity solvents (e.g., DMSO) and demonstrated enhanced fluorescence in solvents ranging from low-polarity (e.g., 1,4-Dioxane) to high-polarity. Notably, by utilizing probe CZ1, we could specifically visualize LDs and captured high-quality images, even eliminating the need for a time-consuming wash procedure. Moreover, CZ1 enabled monitoring of LDs dynamic changes in-real time within live cells, and importantly, it could be used to effectively distinguish normal and NAFLD tissues at both the organ and in vivo level. This exceptional property of probe CZ1 provides a practical tool for the diagnosis and intervention of NAFLD.