In this paper, a colorimetric and "turn-on" fluorescent sensor (Py-Si-Fe3O4@SiO2 NPs) for Hg(2+) detection was designed with pyrene derivative covalently grafted onto the surface of magnetic core/shell Fe3O4@SiO2 nanoparticles using the silanol hydrolysis approach. The Py-Si-Fe3O4@SiO2 inorganic-organic hybrid material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray power diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and fluorescence emission. The results of fluorescence spectra showed that the resultant multifunctional nanoparticles exhibited selective turn-on type fluorescence enhancement with Hg(2+). In addition, the presence of magnetic Fe3O4 nanoparticles in the sensor Py-Si-Fe3O4@SiO2 NPs would also facilitate the magnetic separation of Hg(2+)-Py-Si-Fe3O4@SiO2 from the solution. The as-prepared chemosensor was also successfully applied to detect Hg(2+) in environmental water samples and serum sample. Results from confocal laser scanning microscopy experiments demonstrated that this chemosensor was cell permeable and can be used as a fluorescent probe for monitoring Hg(2+) in living cells.
Keywords: Fluorescent sensor; Hg(2+); Living cells; Magnetic core/shell; Py–Si–Fe(3)O(4)@SiO(2) NPs; Water samples and serum sample.
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