Facile Synthesis of Red/NIR AIE Luminogens with Simple Structures, Bright Emissions, and High Photostabilities, and Their Applications for Specific Imaging of Lipid Droplets and Image‐Guided Photodynamic Therapy

Red/near‐infrared (NIR) fluorescent molecules with aggregation‐induced emission (AIE) characteristics are of great interest in bioimaging and therapeutic applications. However, their complicated synthetic approaches remain the major barrier to implementing these applications. Herein, a one‐pot synthetic strategy to prepare a series of red/NIR‐emissive AIE luminogens (AIEgens) by fine‐tuning their molecular structures and substituents is reported. The obtained AIEgens possess simple structures, good solubilities, large Stokes shifts, and bright emissions, which enable their applications toward in vitro and in vivo imaging without any pre‐encapsulation or ‐modification steps. Excellent targeting specificities to lipid droplets (LDs), remarkable photostabilities, high brightness, and low working concentrations in cell imaging application make them remarkably impressive and superior to commercially available LD‐specific dyes. Interestingly, these AIEgens can efficiently generate reactive oxygen species upon visible light irradiation, endowing their effective application for photodynamic ablation of cancer cells. This study, thus, not only demonstrates a facile synthesis of red/NIR AIEgens for dual applications in simultaneous imaging and therapy, but also offers an ideal architecture for the construction of AIEgens with long emission wavelengths. A one‐pot synthetic strategy is described for preparing red‐ and near‐infrared‐emissive aggregation‐induced emission (AIE) luminogens (AIEgens) with simple structures, large Stokes shifts, and bright emissions. These AIEgens can be utilized as lipid droplet‐specific bioprobes in cell imaging and in vivo zebrafish imaging with high photostabilities and brightness. They are also effective in photodynamic cancer cell ablation upon visible light irradiation.