Size and morphological effect of Au-Fe3O4 heterostructures on magnetic resonance imaging

作者：Lin Fang hsin; Peng Hsu Hsia; Yang Ya Han; Doong Ruey an^*

来源：Journal of Nanoparticle Research, 2013, 15(12).

DOI：10.1007/s11051-013-2139-7

• Au-Fe3O4 heterostructure
• Dumbbell-like nanoparticle
• Flower-like nanoparticle
• MRI
• Imaging

Various sizes and morphologies of Au-Fe3O4 heterostructures including dumbbell-like nanoparticles (DBNPs) and flower-like nanoparticles (FLNPs) have been synthesized via thermal decomposition of iron-oleate complex in the presence of different sizes of Au seeds for MR imaging application. The size of Au seeds and the concentration of iron-oleate complex have been proved to be crucial parameters for controlling the morphology of Au-Fe3O4 heterostructures. The use of 5-nm Au seeds can only fabricate Au-Fe3O4 DBNPs, while both DBNPs and FLNPs are produced by using 10-nm Au NPs as the seeds. The obtained Au-Fe3O4 heterostructures are then modified with 8-arm PEG-amine and show a good phase transfer with satisfactory hydrodynamic size for further MR imaging application. The Au-Fe3O4 DBNPs with small Au seeds result in an increase in spin-spin relaxivity, and the r(2) values are 125.5 +/- 13.5, 118.3 +/- 2.3, and 143.8 +/- 3.2 mM(-1) s(-1) for 5-nm Au-Fe3O4 DBNPs, 10-nm Au-Fe3O4 DBNPs, and 10-nm Au-Fe3O4 FLNPs, respectively. The Au-Fe3O4 FLNPs shows an increased relaxivity when compared with that of Au-Fe3O4 DBNPs, presumably attributed to the magnetic coupling effect among Fe3O4 domains on the surface of Au seeds.

• 出版日期2013-11-30
• 单位清华大学