A novel dehydroabietic acid-based turn-on fluorescent probe for the detection of bisulfite and its application in live-cell and zebrafish imaging

In this paper, a turn-on fluorescent probe (DBE) was designed and synthesized for probing bisulfite (HSO3−) by coupling dehydroabietic acid-based benzimidazole derivatives with ethyl cyanoacetate moiety. The structure of the compound was characterized using its UV-Vis, 1H-NMR, 13C-NMR and HRMS spectra. The probe showed significant selectivity and sensitivity towards HSO3− compared to other analytes in DMF/PBS buffer (3/7, v/v, 10 mM, pH = 7.4), and exhibited a detection limit at the nanomolar level (3.2 nM), fast response time (140 s) and good pH stability (6–10) in living systems. Furthermore, this probe was successfully utilized for the fluorescence imaging of HSO3− in living zebrafish and MCF-7 cells with remarkable lysosome-targeting properties.