A new CoFe2O4–Cr2O3–SiO2 fluorescent magnetic nanocomposite

Abstract

A combined sonochemical co-precipitaion method has been developed for the synthesis of a CoFe₂O₄–Cr₂O₃–SiO₂ magnetic nanocomposite. The synthesis involved the pre-synthesis of CoFe₂O₄–Cr₂O₃ nanoparticles, which were subsequently coated with SiO₂ by treatment with tetraethyl orthosilicate. It was observed that the as-prepared CoFe₂O₄–Cr₂O₃–SiO₂ nanocomposite exhibits photoluminescence properties without the addition of any external fluorescent marker. The fluorescent magnetic nanoparticles (FMNPs) had a typical diameter of 30 ± 5 nm and a saturation magnetization of 5.1 emu g^-1 at room temperature. This as-prepared nanocomposite was used for staining cultured HeLa cells for fluorescence imaging.