Real-time tracking the mitochondrial membrane potential by a mitochondria-lysosomes migration fluorescent probe with NIR-emissive AIE characteristics

Abstract Mitochondrial membrane potential (MMP) is a critical parameter representing mitochondrial function and cellular activities. The development of a robust and convenient method for real-time tracking the MMP changes is still highly desirable and urgently needed. Herein, we presented a novel mitochondria-lysosomes migration fluorescent probe (CSP) with aggregation-induced emission (AIE) characteristics and near-infrared (NIR) solid-state emission for in situ real-time tracking MMP variations. The cationic probe CSP exclusively stained mitochondria with normal MMP; once MMP decreases, CSP could be released from mitochondria and migrated to lysosomes; with the recovery of MMP, CSP could move back to the mitochondria. Interestingly, the average colocalization coefficient (CLC) between CSP and a commercial lysosome-specific dye (LB-NIR) have been successfully served as a reliable and practical MMP parameter for real-time tracking the dynamic changes of MMP. Moreover, other unique features of AIEgens such as large Stokes shift (197 nm), high fluorescence quantum yield (9.8 %), excellent photostability and wash-free bioimaging, together make CSP a promising tool for real-time tracking MMP during the mitochondria-involved pathophysiologic processes.