Mesoporous Cerium Phosphonate Nanostructured Hybrid Spheres as Label-Free Hg2+ Fluorescent Probes

Porous phosphonate-based organic-inorganic hybrid materials have been shown to have novel and amazing physicochemical properties due to the integration of superiorities from both inorganic components and organic moieties. Herein, mesoporous cerium phosphonate nanostructured hybrid spheres are prepared with the assistance of cationic surfactant cetyltrimethylammonium bromide while using ethylene diamine tetra(methylene phosphonic acid) as the coupling molecule. The resulting hybrid is constructed from the cerium phosphonate nanoparticles, accompanied by high specific surface area of 455 m(2) g(-1). The uniform incorporation of rare-earth element cerium and organophosphonic functionalities endows mesoporous cerium phosphonate with excellent fluorescence properties for the development of an optical sensor for selective Hg2+ detection on the basis of the fluorescence-quenching mechanism. The signal response of mesoporous cerium phosphonate against the Hg2+ concentration is linear over the range from 0.05 to 1.5 mu mol L-1, giving a limit of detection of 16 nmol L-1 (at a signal-to-noise ratio of 3). Most of the common physiologically relevant cations and anions did not interfere with the detection of Hg2+. This label-free system provides a promising platform for further use in bioimaging and biomedical fields.