A Novel Mercury-Sensitive Fluorescent Nano-chemosensor using new Functionalized Magnetic core-shell Fe3O4@SiO2 Nanoparticles

In this work, a novel Hg2+ sensitive fluorescent chemosensor is constructed. The proposed nano-chemosensor was prepared through the preparation of 3-(benzo[d]thiazol-2-yl)-7 hydroxy-2H-chromen- 2-one functionalized silica nanoparticles which has high magnetization properties (BTC-Fe O4@SiO2). The ûnal product was characterized by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UVvisible absorption and ûuorescence emission. The material was found to demonstrate selective interactions with Hg2+ ions. This interaction is most probably due to the presence of the ûuorophore moiety at the surface of nanomaterial. Fluorescence measurements revealed that the emission intensity of the Hg2+-bound with the magnetic core-shell Fe3O4@SiO2 NPs increases signiûcantly upon addition of various concentrations of Hg2+, while in case of other mono, di, trivalent cations no changes or weak changes in the intensities were observed. The enhancement of ûuorescence is attributed to the strong covalent binding of Hg2+ ions with the binding constant value of 1.7×105/M. The sensor can be applied for analysis of mercury in environmental sample.