Multifunctional organic-inorganic composite luminescent nanospheres

A simple general strategy was successfully developed for the preparation of magnetic-luminescent multifunctional nanocomposites by incorporating fluorescent (pyrene) and magnetic (Fe(3)O(4)) components simultaneously into a poly(styrene-co-methacrylic acid) [poly(St-co-MAA)] copolymer matrix. The nanospheres so prepared were characterized using scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analysis. The prepared magnetic-fluorescent inorganic-organic nanocomposites have excellent magnetic and photoluminescent properties. They can be used in magnetic separation of trace amounts of sample, fluorescence detection and imaging applications, including magnetic resonance imaging (MRI) and fluorescence imaging. The fluorescence quenching of the nanospheres in the presence of different amounts of Cu(2+) ions was also investigated. Under optimal experimental conditions, the relative fluorescence intensity of the composite nanosphere colloidal solution is proportional to the concentration of Cu(2+) ions, which indicates that these multifunctional nanocomposites can be used for the magnetic separation and fluorescence detection of Cu(2+) ions.