A novel coumarin/quinolinium-based fluorescent probe for the detection and bioimaging of intracellular biothiols

Abstract

Biothiols, including cysteine (Cys), homocysteine (Hcy), and glutathione (GSH), are crucial redox regulators whose dysfunction is implicated in numerous pathological conditions. Herein, we present a coumarin/quinolinium-based probe, SDS-Bio, which could detect biothiols via Michael addition-triggered disruption of intramolecular charge transfer, producing a blueshift (480 to 450 nm) and robust fluorescence turn-on at 495 nm. This probe exhibits rapid response kinetics, low detection limits, high selectivity and excellent photostability towards these biothiols under physiological pH conditions. The probe SDS-Bio could detect endogenous and exogenous biothiols in living cells. Furthermore, SDS-Bio was successfully applied to monitor the changes in endogenous biothiols during Erastin-induced ferroptosis. The present results suggest that SDS-Bio can be a potential tool for bioimaging intracellular biothiols and investigating the mechanisms of ferroptosis-associated disease.