AIE Luminogens for Bioimaging and Theranostics: from Organelles to Animals

High-quality fluorescence bioimaging requires organic exogenous contrast agents with biocompatibility, brightness, and photostability. The recently discovered and rapidly developed aggregation-induced emission luminogens (AIEgens) are excellent candidates because they exhibit enhanced emission upon the restriction of intramolecular motions (RIM) effect. AIEgens are individually lit up once bound with biomolecules or influenced by the surrounding bio-environment, and abundant biological information can be acquired on the basis of high-sensitivity fluorescence imaging. In addition, AIEgen-incorporated nanoparticles possess bright fluorescence and improved photostability, which is beneficial to long-term bioimaging with high contrast and spatial resolution. In this review, we summarize the latest advances in AIEgen-based fluorescence bioimaging, as well as the relevant applications in theranostics.