A benzothiadiazole-based polar fluorescent probe for targeting lipid droplets in living cells

A polarity-sensitive fluorescent probe based on benzothiadiazole that could precisely target lipid droplets in living HeLa cells was synthesized. Experiments demonstrated that the UV absorption and fluorescence emission wavelengths of BTD-LD significantly red-shifted in different polar solvents as the polarity of the solvents decreased. Noticeable changes in fluorescence intensity enabled the effective detection of microenvironmental polarity changes. Cell colocalization imaging experiments revealed that BTD-LD efficiently penetrated cell membranes and specifically targeted lipid droplets. These results suggested that BTD-LD could precisely detect lipid droplets, which could be applied for studying their functions and disease-related mechanisms.