The visualization of lysosomal and mitochondrial glutathione via near-infrared fluorophore and in vivo imaging application

Fluorescent probes with novel organelle-labeling manner can contribute to verify the unraveling cellular functions of various organelles. In this work, we reported a glutathione (GSH) specific near-infrared fluorescent probe, which was composed of a near-infrared cyanine moiety, a morpholine-containing naphthalimide and a thiol-reactive site. The cationic fluorophore cyanine can be capable of targeting mitochondria while the morpholine group can serve as the lysosome-targeting role. The optical behavior in vitro showed that this probe showed high selectivity toward GSH over other thiol-containing amino acids in near-infrared channel. Similar selectivity was found in bioimaging of living cells. The fluorescence co-localization images confirmed that the probe had a good mitochondria-targeting and lysosome-targeting capability in living cells. Moreover, the probe was endowed with near-infrared emission which was favorable for marking the GSH in vivo. We anticipate that such dual targeting strategy will be helpful to develop multiple organelle-targeting fluorescent probes.