Authors: B. Liu, D. Wang, W. Huang, W. Xie, M. Yu, A. Yao
Affilation: Tongji University, China
Pages: 297 - 301
Keywords: composites, nanostructures, chemical synthesis, magnetic properties, luminescence
A new kind of water-soluble luminescent superparamagnetic nanocomposite particles has been synthesized using a modified Stöber method combined with an electrostatic assembly process. Fe3O4 nanoparticles with the size of 10 nm were uniformly coated with silica shell, forming the core-shell SiO2/Fe3O4 nanoparticles, and then 3-aminopropyltrimethoxysilane (APTS) was used to terminate the silica surface with amino groups. After the amino groups being protonated, the negative charged CdSe Quantum Dots (QDs) were electrostatic assembled onto the surface of SiO2/Fe3O4 nanoparticles, forming CdSe-QDs/SiO2/Fe3O4 nanocomposite particles. X-ray diffraction (XRD), transmission electron microscopy (TEM), microelectrophoresis, UV-vis absorption and emission spectroscopy and magnetometry were applied to characterize the nanocomposite particles. Dense CdSe QDs were immobilized on the silica surface. The thickness of silica shell was about 35 nm and the particle size of the final products was about 100 nm. The particles exhibited favorable superparamagnetic and photoluminescenct properties. These nanocomposite particles are expected to serve as luminescent markers and are capable of being driven by a magnetic field to a specific target.