A new ratiometric fluorescent chemodosimeter for sensing of Hg2+ in water using irreversible reaction of arylboronic acid with Hg2+

We synthesized a highly selective ratiometric fluorescent chemodosimeter (1) for Hg2+ on the basis of the displacement reaction of phenylboronic acid with Hg2+ ions. The fluorescent chemodosimeter sensitively detected Hg2+ ions by two emission maxima with a 100 nm different wavelength. 1 exhibited remarkable detection property for Hg2+ such as high selectivity, high sensitivity, large fluorescent signal changes, ratiometric detection, and well-operation in aqueous solutions. Especially, the coexisting other metal ions did not interfere considerably with the ratiometric detection of Hg2+. The binding mode study indicated that the displacement reaction of 1 with Hg2+ provided the covalent adduct (2) of mercury ion, which aggregated in aqueous solution, resulting in the large fluorescent signal changes. Utilizing the ratiometric chemodosimeter with the low detection limit (15.2 nM) for Hg2+, nanomolar concentrations (0 similar to 350 nM) of Hg2+ was successfully detected in aqueous solutions. 1 provided a ratiometric fluorescent detection method to quantify low levels of Hg2+ in groundwater and tap water samples.

Automated summary

A highly selective ratiometric fluorescent chemodosimeter was synthesized for the detection of Hg2+, which showed remarkable detection properties including high selectivity and sensitivity, large fluorescent signal changes, and well-operation in aqueous solutions. The displacement reaction between phenylboronic acid and Hg2+ ions provided a covalent adduct of mercury ion, leading to significant fluorescent signal changes when aggregated in aqueous solution. With a low detection limit of 15.2 nM, nanomolar concentrations of Hg2+ could be successfully detected, providing a ratiometric fluorescent detection method for quantifying low levels of Hg2+ in groundwater and tap water samples.