Sensitive and quantitative characterization of clinically relevant biomarkers can facilitate disease diagnosis and treatment evaluation. Magnetic nanomaterials and their biosensing strategies have recently received considerable attention. Magnetic signals experience little interference from native biological background as most biological molecules have negligible magnetic susceptibilities and thus appear transparent to external magnetic fields. Because of this unique property, magnetic sensing can be applied to both in vivo deep tissue imaging as well as ex vivo point-of-care diagnostics. To exploit this mode of magnetic detection, new advancements in both magnetic material syntheses and sensing technologies have been made. This review focuses on recent developments of magnetic nanomaterials as image contrast agents and diagnostic sensors. These developments have not only enabled precise control of magnetic nanomaterial properties but also expanded the reach of magnetic detection for biomedical diagnostics.
Keywords: Magnetic nanoparticles (NPs); ex vivo detection; in vivo imaging; miniaturized sensors.