Tiny magnetic particles show unexpected monopole behavior with chiral coatings
Researchers discovered that superparamagnetic iron oxide nanoparticles coated with chiral molecules behave like magnetic monopoles—creating short-range magnetic fields that respond differently based on molecular handedness. The finding could unlock new applications in targeted drug delivery, magnetic memory storage, and precision catalysis by enabling better control over how these widely-used nanoparticles interact with magnetic environments.
Originaltitel: Magnetic Monopole-Like Behavior in Superparamagnetic Nanoparticle Coated With Chiral Molecules
<p>Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted wide attention due to their promising applications in biomedicine, chemical catalysis, and magnetic memory devices. In this work, the force is measured between a single SPION coated with chiral molecules and a ferromagnetic substrate by atomic force microscopy (AFM), with the substrate magnetized either toward or away from the approaching AFM tip. The force between the coated SPION and the magnetic substrate depends on the handedness of the molecules adsorbed on the SPION and on the direction of the magnetization of the substrate. By inserting nm-scale spacing layers between the coated SPION and the magnetic substrate it is shown that the SPION has a short-range magnetic monopole-like magnetic field. A theoretical framework for the nature of this field is provided.</p>