Fluorescent mesoporous organosilicas for selective monitoring of Hg2+ and Fe3+ ions in water and living cells

A new fluorescent mesoporous organosilicas bearing ethidium bromide in the framework was conveniently synthesized using 3-aminopropyltriethoxysilane as bridging organosilane functionality. Powder X-ray diffraction, N-2 sorption, transmission electron microscopy and scanning electron microscopy, and UV-visible absorption and fluorescence spectroscopy have been employed to characterize the materials. This material showed a selective monitoring of Hg2+ and Fe3+ ions with fluorescence quenching and visible color transition over a wide range of tested metal ions, which is due to the selective interactions of Hg2+ and Fe3+ ions with integrated functional groups at its pore wall framework. The experimental measurements reveal that the mesoporous organosilica material shows Hg2+ and Fe3+ ion selectivity upon addition of various concentrations of other competitive metal ions. Thus, the synthesized mesoporous organosilicas could monitor Hg2+ and Fe3+ ions in water and biological cells even in the trace amount. (C) 2014 Elsevier Inc. All rights reserved.