Fig. 1. Design, synthesis, and photophysical properties of fluorescent probes. (a) Molecular structure of Lipi-QL and its calculation results by TD-DFT; (b) absorption emission spectra of Lipi-QL in different polar organic solvents; (c) fluorescence spectra and fluorescence photographs of Lipi-QL in different dioxane solutions; (d) fluorescence spectra and fluorescence photographs of BODIPY 493/503 in different dioxane solutions

Fig. 2. Co-localization experiments of Lipi-QL and Ph-Red in HeLa cells (scale bar is 10 μm). (a) Green imaging channel of Lipi-QL; (b) red imaging channel of Ph-Red; (c) superimposed images of two fluorescence channels and bright field

Fig. 3. Comparison of staining selectivity between Lipi-QL and BODIPY 493/503 in HeLa cells under different concentrations (scale bar is 10 μm)

Fig. 4. 3D confocal imaging of HeLa cells stained with Lipi-QL

Fig. 5. Multicolor confocal imaging of live Hela cells ( scale bar is 10 μm). (a) Hoechst 33342-stained nucleus; (b) Lipi-QL-stained lipid droplets; (c) Lyso Tracker Red-stained lysosomes; (d) Mito Tracker Deep Red-stained mitochondria; (e) merged images of four fluorescence channels