Synthesis of monodisperse magnetite nanoparticles via chitosan–poly(acrylic acid) template and their application in MRI

• Published in: Journal of alloys and compounds 2009-04, Vol.473 (1), p.356-362
• Main Authors: Feng, B., Hong, R.Y., Wu, Y.J., Liu, G.H., Zhong, L.H., Zheng, Y., Ding, J.M., Wei, D.G.
• Format: Article
• Language: English
• Subjects: Chemical synthesis; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of nanostructures; Magnetization; Materials science; Nanopowders; Nanoscale materials and structures: fabrication and characterization; Nanostructured materials; Physics; Transmission electron microscopy (TEM)
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2008.05.094

Ultrasmall magnetite nanoparticles were prepared by using chitosan–polyacrylic acid (CS–PAA) nanospheres as template. The CS–PAA hollow nanospheres could be prepared by polymerization of acrylic acid monomers in the presence of chitosan. The Fe 3O 4 loading was done by dissolving FeCl 3·6H 2O and FeSO 4·7H 2O into CS–PAA nanospheres solution followed by adding NH 4OH. In finally, CS–PAA template could be removed by adjusting with HCl to pH < 1. The obtained particles were characterized by dynamic light scattering (DLS) in aqueous solution and observed by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and X-ray. The results revealed that the Fe 3O 4 nanoparticles were 3–5 nm in size with excellent dispersibility. From the magnetometer measurements data, the particles exhibited superparamagnetic property with saturation magnetizations of 40.7 emu/g. The MRI experiment on living rabbit showed that nanoparticles prepared by the current synthetic approach had a significant magnetic resonance signal enhancement in T2-weighted image of lymph nodes.