A novel dehydroabietic acid-based fluorescent probe for detection of Fe3+ and Hg2+ ions and its application in live-cell imaging

Abstract

A novel dehydroabietic acid-based fluorescent probe (DBH) containing 2,4-diarylbenzimidazole moiety was designed and synthesized, and the compound was characterized by its UV–Vis, FT-IR, 1H NMR, 13C NMR and ESI-MS spectra. DBH could be used for the detection of Fe3+ and Hg2+ through the selective fluorescence quenching in EtOH/H2O solution. The probe DBH showed excellent selectivity and sensitivity towards Fe3+ and Hg2+ over other metal ions. The limits of detection were calculated as 3.12 × 10−8 M and 3.10 × 10−8 M, respectively. Especially, DBH have a wide pH range for ion detection (5 ~ 12), and a short response time (10 s). Job’s plot method in combination with ESI-MS and FT-IR spectra was used to determine the stoichiometry of DBH-Fe3+/Hg2+ complexes as both 2:1. Moreover, DBH exhibited low cytotoxicity to MCF-7 and SMCC-7721 cells (IC50 > 100 μM). In the fluorescent cell imaging experiments, DBH could be used as a prominent intracellular probe for the detection of Fe3+ and Hg2+ in living cells.