A Sensitive Fluorescent Probe for Homocysteine/Cysteine in Pure Aqueous Media and Mitochondria

Biothiols, involving homocysteine (Hcy), cysteine (Cys), and glutathione (GSH), are very important in physiological and pathological processes and play critical roles in the sustainment of the cellular equilibrium. In order to grasp more information about physiological and pathological processes and make new advances in the medical industry, it′s indispensible to develop more useful tools to detect biothiols. Herein, we have successfully prepared a novel mitochondrial homocysteine/cysteine-selective fluorescent probe. Based on nucleophilic aromatic substitution (SNAr) and intramolecular rearrangement cascade reactions, this fluorescent probe shows not only a mitochondria-targeting property but also a stable function in pure aqueous media with rapid and sensitive responses toward Hcy/Cys. For one thing, it is able to realize fluorescence imaging of Hcy/Cys in mitochondria. For another, we can acquire information about biothiol-relevant redox status via this potential probe. We hope this probe will help us to broaden our knowledge about the effects of biothiols especially Hcy/Cys.