A novel fluorescence probe for the selective detection of cysteine in aqueous solutions and imaging in living cells and mice

Abstract

A novel fluorescent probe based on hydroxyquinoline conjugated with a charged trimethylindolenine unit Toc-Ac was developed, which exhibited long wavelength emission (560 nm) and a large Stokes shift (∼140 nm) due to the intrinsic mechanism of the intramolecular charge transfer process. The probe Toc-Ac showed a highly sensitive response to Cys (the detection limit was 3.86 × 10⁻⁸ M) in aqueous solution and was successfully applied for detecting endogenous Cys in living cells and mice.