A viscosity-sensitive fluorescent probe with a large Stokes shift for monitoring lipid droplets and its application in cell, tobacco leaf, and food detection†

Abstract

Lipid droplets are important organelles in eukaryotic cells and play an integral role in cellular metabolism. Abnormal changes in intracellular lipid droplets are usually associated with the occurrence of many diseases. Studying the changes in lipid droplet status in cells is of great significance for understanding the regulatory mechanism of intracellular lipid metabolism and the pathogenesis of some related diseases. This paper reports a novel lipid droplet fluorescent probe, LDCN. The D–A–D structure of the probe LDCN brings a good TICT effect, which makes the probe have excellent polarity and viscosity sensitivity. In addition, LDCN has excellent selectivity, good pH stability, and a large Stokes shift (114 nm). LDCN showed good co-localization with commercial lipid droplet dyes in both HeLa cells and tobacco seedling leaf cells. The results showed that the probe was able to selectively sense lipid droplets in living cells. Meanwhile, LDCN could also be used for freshness detection of juice drinks.