Resonance-Based Detection of Magnetic Nanoparticles and Microbeads Using Nanopatterned Ferromagnets

Abstract

Magnetic biosensing, which uses functionalized magnetic particles to label and detect biological analytes, is attractive for future ``point-of-care'' medical diagnostic applications. The authors demonstrate detection of a wide range of magnetic particle types and sizes (from 6 nm to 4 $\ensuremath{\mu}$m) via their influence on geometrically nanoconfined ferromagnetic resonance modes. This approach provides a novel magnetic particle detection modality extending all the way down to the nanoscale.