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Magnetic iron oxide nanoparticles (IONPs) are heavily explored as diagnostic and therapeutic agents due to their low cost, tunable properties, and biocompatibility. In particular, upon excitation with an alternating current (AC) magnetic field, the NPs generate localized heat that can be exploited for therapeutic hyperthermia treatment of diseased cells or pathogenic microbes. In this review, we focus on how structural changes and inter-particle interactions affect the heating efficiency of iron oxide-based magnetic NPs. Moreover, we present an overview of the different approaches to evaluate the heating performance of IONPs and introduce a new theranostic modality based on magnetic imaging guided–hyperthermia.
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Magnetic Tunability via Control of Crystallinity and Size in Polycrystalline Iron Oxide Nanoparticles
Abstract Iron oxide nanoparticles (IONPs) are widely used for biomedical applications due to their unique magnetic properties and biocompatibility. However, the controlled synthesis of IONPs with tunable particle sizes and crystallite/grain sizes to achieve desired magnetic functionalities across single‐domain and multi‐domain size ranges remains an important challenge. Here, a facile synthetic method is used to produce iron oxide nanospheres (IONSs) with controllable size and crystallinity for magnetic tunability. First, highly crystalline Fe3O4IONSs (crystallite sizes above 24 nm) having an average diameter of 50 to 400 nm are synthesized with enhanced ferrimagnetic properties. The magnetic properties of these highly crystalline IONSs are comparable to those of their nanocube counterparts, which typically possess superior magnetic properties. Second, the crystallite size can be widely tuned from 37 to 10 nm while maintaining the overall particle diameter, thereby allowing precise manipulation from the ferrimagnetic to the superparamagnetic state. In addition, demonstrations of reaction scale‐up and the proposed growth mechanism of the IONSs are presented. This study highlights the pivotal role of crystal size in controlling the magnetic properties of IONSs and offers a viable means to produce IONSs with magnetic properties desirable for wider applications in sensors, electronics, energy, environmental remediation, and biomedicine.
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- PAR ID:
- 10523682
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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