Abstract
The sensitive visualization of cysteine (Cys) levels in the Golgi apparatus of living cells during drug-induced oxidative stress is of significant importance for improving theranostic efficiency and optimizing drug design. Herein, a simple Cys-specific ratiometric fluorescent probe (ICN-Cys) was reasonably constructed using 4-CF3-7-aminoquinoline derivate as fluorophore and Golgi-targeting moiety and isocyano moiety as specific reaction site of Cys. This probe has been proven to hold many outstanding features of high specificity and sensitivity (detection limit of 4.8 μM), satisfactory response speed (within 30 min), ratiometric detection (F515/F385), good biocompatibility, unique Golgi-targetability. Moreover, this probe can be used to monitor exogenous and endogenous Cys in the Golgi apparatus of living cells, and distinguish cancerous cells from normal cells. As expected, under oxidative stress induced by drug treatments, probe ICN-Cys successfully tracked the dynamic fluctuations of Cys levels in living cells. Furthermore, probe ICN-Cys was used to visualize Cys level changes in pathways associated with both the promotion and inhibition of ferroptosis. In summary, this work not only demonstrates isocyano moiety can serve as an ideal recognition receptor of Cys, but also offers a promising analytical tool for the visualization of Cys levels in the Golgi apparatus during Cys-related diseases.
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•A novel Golgi-targeting Cys-specific fluorescent probe was developed.•An isocyano moiety was firstly proposed as highly selective recognition site of Cys.•The detection of native and exogenous/endogenous Cys was successfully achieved.•The fluctuations of Cys levels during drug-induced oxidative stress were monitored.