A mini-review of functionalized magnetic Fe3O4 nanoparticles: From fundamentals to application

Surface-functionalized magnetic iron oxide (F-Fe₃O₄) nanoparticles have attracted close attention from researchers in various fields due to their stable chemical properties, good magnetic responsiveness, and biocompatibility. At present, F-Fe₃O₄ nanoparticles are widely used in many fields, including interfacial separation, catalysis, biosensing, and medical nuclear magnetic resonance imaging. However, there are still cognitive blind spots regarding the application of F-Fe₃O₄ nanoparticles in different fields. Herein, first of all, the basic theories of magnetic Fe₃O₄ nanoparticles were systematically discussed, including structural characteristics, magnetic behavior, preparation methods, and characterization techniques. Then, based on the fundamental theories, the applications of F-Fe₃O₄ nanoparticles in important fields (such as oil–water interface separation, photocatalysis, thermal catalysis and electrocatalysis, biosensing and medical magnetic resonance imaging) were systematically reviewed. Finally, the paper delves into the scientific challenges faced by F-Fe₃O₄ nanoparticles in various application fields, thereby providing potential insights and directions for the further development of F-Fe₃O₄ nanoparticles. This review is helpful to deepen the understanding of the scientific issues faced by F-Fe₃O₄ nanoparticles and provides theoretical guidance for the development and application of F-Fe₃O₄ nanoparticles. Additionally, this review provides the necessary engineering theoretical guidance to accelerate the large-scale commercial application of F-Fe₃O₄ nanoparticles, which possess significant scientific value and profound social significance.