A new ratiometric fluorescent chemodosimeter based on an ICT modulation for the detection of Hg2+

• A new chemodosimeter S1 based on phenanthrenequinone fluorophore has been designed and synthesized.
• Hg2+-induced dethioacetalization switching an ICT process has been strategized and demonstrated for selective sensing mechanism towards Hg2+.
• S1 exhibits a selective ratiometric fluorescent response towards Hg2+ over other coexisting cations/anions in a wide pH range.
• Fluorogenic method for the quantitative detection of Hg2+ has been established by using S1.

We design and synthesize a new ratiometric fluorescent chemodosimeter (S1) for the selective and sensitive detection of Hg2+. Upon addition of Hg2+, the emission of the S1 exhibits a large bathochromic shift from 393 to 515 nm (up to 122 nm) which is ascribed to an intramolecular charge transfer process in the resultant. The Hg2+-induced dethioacetalization for sensing mechanism has been demonstrated by using high-performance liquid chromatography analysis of the sensing process. The interference experiments further demonstrate that S1 exhibits very high selectivity towards Hg2+ over other coexisting cations/anions. Subsequently, a good linearity of the concentrations of Hg2+ (0–15 μM) vs the ratiometric signals (I515/I393) allows a fluorogenic method for the quantitative detection of Hg2+, with the limitation of detection determined to be 5.22 × 10−7 M.

A new chemodosimeter S1 based on phenanthrenequinone fluorophore has been designed and synthesized. By using S1, a fluorogenic method for the quantitative detection of Hg2+ is further established.Figure optionsDownload as PowerPoint slide