Magnetically recoverable fluorescence chemosensor for the adsorption and selective detection of Hg2+ in water

Abstract

In order to conveniently and effectively detect the heavy metal ion Hg²⁺ existing in water, a magnetic fluorescence chemosensor has been strategically prepared by immobilizing a Rhodamine B derivative RhB–tris(2-aminoethyl)amine on Fe₃O₄@SiO₂–Au@PSiO₂ composites via gold particles. The adsorption and detection for Hg²⁺ ions were investigated with fluorophotometry. This chemosensor shows high sensitivity and high selectivity for Hg²⁺ over other metal cations owing to the ring opening of the rhodamine fluorophore selectively induced by Hg²⁺. In addition, the presence of Fe₃O₄ in the sensor also facilitates the magnetic separation of the Fe₃O₄@SiO₂–Au–Hg²⁺@PSiO₂ from the solution.