A novel cysteine fluorescent probe based on benzothiazole and quinoline with a large stokes shift and application in living cell and mice.

In this study, a novel fluorescent probe, Doc-Ac, was prepared and displayed highly selectivity to Cys with a relatively large Stokes shift (165 nm) and fast fluorescence response (within 7 min.) in almost 100 % aqueous solution at a physiological pH. In addition, the probe displayed low toxicity and had been successfully used in fluorescence imaging of endogenous Cys and selectively discriminate the intracellular Cys from GSH and Hcy in living cells and mice. To the best of our knowledge, this is the first report on the real-time visualization and fast response of Cys in a living animal in almost 100 % aqueous solution. [Display omitted] • The probe is easy to be prepared. • The probe can rapidly, high sensitivity and selectivity detect Cys with a large Stokes shift in aqueous solution. • The probe successfully applied to detect endogenous Cys in living cells and mice. A novel fluorescent probe based on hydroxyquinoline conjugated with benzothiazolyl unit dye Doc-Ac was prepared. The results of fluorescent and absorption spectroscopic responses towards amino acids showed that the probe had a capability of rapidly and selectively detecting cysteine over other amino acids with a large stokes shift in aqueous solution. The sensing mechanism was proved by the proton NMR and high resolution mass spectrometry analysis. The fluorescence images indicated that this probe could discriminate the exogenous/endogenous cysteine in living cells and mice. [ABSTRACT FROM AUTHOR]