Mitochondria-targeted smart AIEgens: Imaging and therapeutics

Mitochondria are not only the main energy source of the cell but are also involved in the regulation of important physiology and processes of diseases including cancers. Therefore, mitochondria have been regarded as an important research target to reveal the mechanism of disease regulation and tumor treatment. Compared to conventional probes, thanks to their merits including resistance to aggregation-caused quenching capability, larger Stokes shift, high photostability, good biocompatibility as well as easy preparation, aggregation-induced emission luminogens (AIEgens) have become one of the research hotspots. Intriguingly, numerous mitochondria-targeted smart AIEgens have been fabricated in recent year to dynamically monitor behaviors of mitochondria or effectively kill tumors through activating mitochondria-regulated cell death pathways. In this review, we provide the systematic information of working mechanisms of aggregation-induced emission (AIE), design principles of mitochondria-targeted AIEgens, examples of AIEgnes for imaging mitochondria and detecting bio-species in mitochondria, and the relevant biomedical applications in theranostics. Additionally, the challenges and prospects of mitochondria-targeted AIEgens for imaging and therapeutics are also presented.