Preparation and formation mechanism of nanocomposites with fluorescent and magnetic properties

Fluorescent magnetic nanocomposites were successfully synthesized using the self-prepared Fe3O4 magnetic liquid and CdTe quantum dots (QDs) as precursors. High-resolution transmission electron microscopy, selected area electron diffraction, energy-dispersive spectroscopy and Fourier transform infrared spectroscopy were used to characterize the size, morphology, structure and composition of the nanocomposites. A fluorescent microscope was used to observe their micro-morphology. Magnetic and optical properties were characterized by a vibrating sample magnetometer and fluorescent spectrophotometer, respectively. The characterized results indicated that the Fe3O4 nanoparticles had been successfully combined with CdTe QDs. The products could exist stably in the aqueous phase, and had better biocompatibility. It was found that the nanocomposites, which had higher magnetization intensity and better fluorescent properties synchronously, were fabricated by the formation of chemical bond with amide structure. Thus this type of nanocomposite could be applied in various science and technology fields in the future. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.