Two kinds of bifunctional architectures combining the useful functions of a superparamagnetic nanoparticle and a near-infrared luminescent lanthanide complex into one material (denoted as Fe3O4@SiO2@Ln-PABI, PABI = N-(4-benzoic acid-yl)-N′-(propyltriethoxysilyl)urea, Ln = Nd and Yb) have been prepared via two main steps by a modified Stöber method and the layer-by-layer assembly technique. The two obtained architectures have been characterized by FTIR spectra, X-ray diffraction, transmission electron microscopy, emission spectroscopy, and vibrating sample magnetometer. These bifunctional nanocomposites exhibit superparamagnetic behaviour, high fluorescence intensity and color purity. Such materials with superparamagnetic and lanthanide-based near-infrared luminescence properties have potential applications in the field of biological luminescent labels.
