Isothiocyanate can be used as a highly specific recognition site for fluorescent cysteine probes

Abstract

Cysteine (Cys) is an essential biothiol and amino acid molecule, playing important roles in many physiological and pathological events. As a biomarker of many diseases, Cys has important clinical significance. Accordingly, it is of great significance to develop an efficient and specific detecting method for Cys in life systems. We report herein a new approach that isothiocyanate (ITC) can be used as an effective new specific recognition site of Cys to develop effective probes for the detection of Cys in life systems. To demonstrate the effectiveness of this approach, ITC was attached to an easy-to-prepare coumarin fluorophore and a novel molecular probe (CM-NCS) was synthesized. As expected, the probe could respond rapidly, selectively, and sensitively to Cys and could be well used for the detection of Cys in live cells and zebrafish. All the results demonstrated that the new recognition site (ITC) would provide a good new choice to develop highly Cys-selective probes.