In recent years, high-moment magnetic nanoparticles (MNPs) such as FeCo are attracting intense interest for biomedical applications. The synthesized FeCo MNPs have the specific saturation magnetization up to 226 emu/g that is more than three times higher than that of iron oxide MNPs (~ 70–80 emu/g). Core-shell MNPs are also synthesized to enhance the functionality of high-moment MNPs. Shells like SiO2, Au, and Ag are used for these high-moment MNPs to improve biocompatibility. The sputtering-based gas-phase condensation approach to synthesize high-moment MNPs and core-shell nanostructures are reviewed. The applications of these high-moment MNPs such as magnetic hyperthermia, drug delivery, magnetic resonance imaging (MRI), and biosensing are summarized. The heating efficiency of magnetic hyperthermia and drug delivery could be significantly enhanced by using high-moment MNPs. MNPs with different crystallinity and shapes (such as cubic, spherical, triangular, and octahedral shapes) are also summarized due to their potential applications in MRI. High-moment MNPs could also provide more magnetic signals for giant magnetoresistance (GMR)-based biosensors, which are also reviewed. We believe that the high-moment MNPs are promising candidates for many bio-applications.
Bibliographical noteFunding Information:
This study was financially supported by the Institute of Engineering in Medicine of the University of Minnesota through FY18 IEM Seed Grant Funding Program, the National Science Foundation MRSEC facility program, the Distinguished McKnight University Professorship, the Centennial Chair Professorship, and the Robert F Hartmann Endowed Chair from the University of Minnesota. Parts of this work were carried out in the Characterization Facility, University of Minnesota, which receives partial support from NSF through the MRSEC program.
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- Biocompatible nanoshells
- Gas-phase condensation
- Magnetic nanoparticles