Specific Fluorescence Probes for Lipid Droplets Based on Simple AIEgens

Lipid droplets (LDs), as dynamic
complex organelles, are involved in various physiological processes,
and their numbers and activity are related to many diseases, even
cancer. Hence, locating and concentration monitoring of LDs are very
important to scientific bioresearch and health care. In this work,
we prepared two simple luminogens (FAS and DPAS) via very facile synthetic
procedures and purification. They feature aggregation-induced emission
and excited state intramolecular proton transfer characteristics.
They exhibit large Stokes shifts and bright orange and yellow emissions
in the aggregated state, and the emissions can be reversibly turned
“off”
and “on” for many cycles by controlling buffer pH values.
Both FAS and DPAS are cytocompatible and can selectively accumulate
in and light up the LDs in living cells with superior resolution and
high contrast. They also outperform the commercial LD probes in terms
of photostability. Combining the advantages of high LD-specificity,
good biocompatibility, surperb photostability, and low preparation
cost, FAS and DPAS may become powerful tools to the study on LDs-related
intracellular activities, such as LDs-based pathology and pharmacology.