A photodynamic aggregation-induced emissive (AIE) fluorophore, characterized by near-infrared (NIR) emission, was created based on a fluorescence resonance energy transfer (FRET) donor of appreciable NIR up-conversion nanoparticles (UCNPs) and acceptor of immense fluorescence emissive AIEgen. Hence, the entrapment of the FRET couple into an amphiphilic saponin-based nanoscaled self-assembly demonstrated appealing theranostic functions in producing immense fluorescence emission and cytotoxic reactive oxygen species (ROS).