A novel ratiometric fluorescent probe for selective detection of Hg2+, Cr3+ and Al3+ and its bioimaging application in living cells

Abstract

A novel rhodamine-benzothiazole fluorescent probe L was designed and synthesized which can be selective detection of three kinds of metal ions (Hg2+, Cr3+ and Al3+), through the mechanism of fluorescence resonance energy transfer (FRET). This probe L shows good sensitivity towards Hg2+, Cr3+ and Al3+ even at the sub-micromolar levels, which exhibited ratiometric fluorescence change from colorless to pink in aqueous media in a wide pH range of 5–10. Interestingly, the Job’s plot investigation suggested that L bounding to Hg2+ or Al3+ with a simple 1:1 mode and a 2:1 mode to Cr3+ display different binding modes. Furthermore, the potential utility for biological applications was performed by fluorescence microscopic imaging in live cells. The results indicated that fluorescence probe L was a hopeful candidate for applications in the cell-imaging and safety inspection.