Red‐emissive Dual‐state Fluorogenic Probe for Wash‐free Imaging of Lipid Droplets in Living Cells and Fatty Liver Tissues

Abstract

Lipid droplet (LD) dysfunction can result in various diseases, such as nonalcoholic fatty liver disease. Imaging agents built on dual-state emission (DSE) molecules that fluoresce in both dilute solutions and the aggregated state are receiving attention as this type of probe could provide bright fluorescence signals at variable concentrations, avoiding false signal readout caused by the concentration fluctuation in living systems. Herein, we identified a red emissive molecule featuring DSE, from three newly synthe-sized molecules, for specific detection of LDs in live cells. The bioimaging abilities have been well confirmed by optical spectroscopies, theoretical calculations, cell experiments, as well as animal studies. The DSE probe is effective for LD detection at concentrations ranging from 1 μM to 100 μM while retaining high brightness and signal fidelity. This study provides a knowledge base for the future design of DSEactive fluorescent probes for understanding LD-related diseases.

Push–Pull Fluorescent Dyes with Trifluoroacetyl Acceptor for High-Fidelity Sensing of Polarity and Heterogeneity of Lipid Droplets

“…To understand better the reason for the high specificity of ProCF3 and FrCF3 to LDs, we estimated the log P of these dyes ( c Log P , Figure ), which reflects the oil–water partition coefficient, an important factor for targeting of dyes to LDs . For ProCF3 and FrCF3, c Log P values are 3.77 and 5.98, respectively, being close to that of Nile Red 4.62.…”