A bifunctional fluorescent probe based on PET & ICT for simultaneously recognizing Cys and H2S in living cells

Most reported probes that respond to Cysteine (Cys) and Hydrogen sulfide (H2S) can only identify one analyte, or they were interfered with homocysteine (Hcy) and glutathione (GSH) when recognizing Cys and H2S. In addition, nitrobenzoxadiazole (NBD) ether, as one of thiols recognition sites, inevitably encounters the situation that Cys, GSH and H2S 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 H2S 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 H2S in living cells is promising.