A bifunctional fluorescent probe based on PET & ICT for simultaneously recognizing Cys and HS in living cells.

Most reported probes that respond to Cysteine (Cys) and Hydrogen sulfide (HS) can only identify one analyte, or they were interfered with homocysteine (Hcy) and glutathione (GSH) when recognizing Cys and HS. In addition, nitrobenzoxadiazole (NBD) ether, as one of thiols recognition sites, inevitably encounters the situation that Cys, GSH and HS cannot be distinguished on the same channel at the cellular level. In this work, by introducing NBD ether and NBD amine, we constructed a bifunctional fluorescent probe NJB for dual-site response to Cys and HS via PET & ICT processes. NJB has wonderful selectivity for identifying Cys and HS, with limits of detection as low as 58.4 nM and 81.1 nM, respectively. Interestingly, NJB has been successfully applied to detect Cys and HS in MCF-7 cells. Therefore, the probe that serves as a great tool for inquiring the physiological and pathological functions of Cys and HS in living cells is promising.