The Functionalization of Magnetic Fe3O4@TiO2 by Molecular Motif for the Detection of Mercury (II)

Abstract

2,6-bis(2-thienyl)pyridine (L) molecular receptor showed strong potential for Hg2+ detection. The chelation through S,N,S was confirmed as a main binding mode of the ligand with Hg2+ ion based on the results of 1H NMR. L showed a strong characteristic fluorescence signal at 413 nm in the absence of Hg2+; however, this signal was quenched when Hg2+ was introduced and a new fluorescence signal at 563 nm appeared. L was anchored into the surface of the coated magnetite microspheres (L-Fe3O4@TiO2) through a siloxane template layer and was fully characterized using thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Detailed emission studies showed the ability of the L and L-Fe3O4@TiO2 not only effectively detect Hg2+ but differentiate it from competing Zn2+, Cd2+,Cu2+,Cr3+,Co2+,Ru3+, Fe2+ ions in solution with minimum interference. Magnetic micropsheres decorated by L showed promising performance as single –excitation -single emission sensor for Hg2+ ions and effective mercury uptake.