A near-infrared fluorescent probe based on SNAr reaction for H2S/GSH detection in living cells and zebrafish

Hydrogen sulfide (H 2 S) and biothiols such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), play critical roles in physiological and pathological processes. However, due to the challenge in sensing H 2 S and biothiols simultaneously, it is of great importance to solve this problem in biological processes. Herein, a near-infrared fluorescent probe (HZ-NBD) based on S N Ar reactions was exploited to achieve the sensitive and selective detection of H 2 S and glutathione (GSH) simultaneously in the same conditions. The design strategy was employing dicyanoisophorone based fluorescent dye as the fluorophore, the NBD moiety as a response unit and a quencher of fluorophore. The probe exhibited a low limit of detection to H 2 S (13.2 nM) and GSH (112 nM) as well as a favourable large stokes shift (112 nm). The reaction mechanism was investigated via mass spectra. What's more, owing to the advantages of low cytotoxicity, fast response and strong anti-interference ability, the probe HZ-NBD was successfully applied to bioimage H 2 S and GSH in HepG2 cells and zebrafish.