▎ 摘　　要

Magnetic fluids (MFs) with good dispersion were prepared by speed-controlled co-precipitation method, using polyethylene glycol (PEG-4000) as dispersing agent. To functionalize the MFs with graphene oxide (GO), highly dispersed nano-magnetic particles (NMPs) were firstly prepared by low-temperature freeze-drying technique. 3-aminopropyltriethoxysilane (APTES) was then attached on the surface of NMPs to form amino functionalized NMPs. GO was finally assembled with amino functionalized NMPs, to prepare GO functionalized MFs (GO-NMPs) by electrostatic adsorption. The obtained GO-NMPs were then characterized by FTIR, XRD, TEM, SEM and VSM. Meanwhile, mice were in vivo used as animal model to study biological application of Tc-99(m) labeled GO-NMPs, suggesting that the targeted functionalized magnetic particles had higher magnetic response effect under pulsed magnetic gradient field.