uperparamagnetic iron oxide (SPIO) nanoparticles have demonstrated their practicability as MRI T2-shortening agents for non-invasive cell labeling, drug delivery or tumor detections in clinical practice. Recently, superparamagnetic chemically disordered face-centered cubic (fcc) FePt nanoparticles has also been demonstrated as superior negative contrast agents for MRI. Superparamagnetic FePt nanoparticles, which show high saturation magnetization (MS) compared to SPIO, are expected to be a high performance nanomagnet for magnetic medicine. However, the conventional complicated synthesis procedure and hydrophobicity has limited the potential usage in vitro, in vivo and in clinic. In this work, the simple microwave heating method was utilized for the controlled synthesis of FePt nanoparticles using Fe(acac)3 and Pt(acac)2 as the main reactants in tetra-ethylene glycol. The advantages of this process are its simplicity, the short reaction time and easy preparation. The structure and composition of the FePt nanoparticles were characterized by XRD, TEM and magnetic measurements. By varying the Fe/Pt ratio, power and irradiation time, the microwave assisted synthesis has shown a significant advantage for the rapid production of monodisperse fcc FePt nanoparticle. The prepared FePt nanoparticles can be further capped by cysteine to improve their water solubility. Moreover, magnetic resonance relaxometry reveals that Cys-capped FePt nanoparticles have a high T2-shortening effect with diameter ~3 nm that can induce sufficient cell MRI contrast. In conclusion, we reported the simple, straightforward and stoichiometrically controlled synthetic route of FePt nanoparticles by microwave-assisted method and FePt synthesis with Fe/Pt ratio, power and microwave irradiation time have been investigated and the prepared superparamagnetic FePt can play as a T2 contrast agent for MRI application.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2010: Advanced Materials, CNTs, Particles, Films and Composites
Published: June 21, 2010
Pages: 433 - 435
Industry sector: Advanced Materials & Manufacturing
Topics: Nanoparticle Synthesis & Applications