A red-emitting fluorescent probe for specific detection of cysteine over homocysteine and glutathione with a large Stokes shift

A red-emitting fluorescent probe for selective detection of cysteine was developed based on the conjugated addition/cyclization sequence mechanism. Upon the treatment with cysteine, this probe exhibits a strong fluorescence enhancement (62-fold) and a large Stokes shift (148 nm). The detection limit was calculated to be as low as 6.6 nM based on S/N = 3. Importantly, the practical application of this probe for the selective detection of cysteine was successfully demonstrated in living cells. (C) 2016 Published by Elsevier B.V.