title: Mechanism of magnetic relaxation switching sensing.
abstract: Magnetic relaxation switching (MRSw) assays that employ target-induced aggregation (or disaggregation) of magnetic nanoparticles (MNPs) can be used to detect a wide range of biomolecules. The precise working mechanisms, however, remain poorly understood, often leading to confounding interpretation. We herein present a systematic and comprehensive characterization of MRSw sensing. By using different types of MNPs with varying physical properties, we analyzed the nature and transverse relaxation modes for MRSw detection. The study found that clustered MNPs are universally in a diffusion-limited fractal state (dimension of ~2.4). Importantly, a new model for transverse relaxation was constructed that accurately recapitulates observed MRSw phenomena and predicts the MRSw detection sensitivities and dynamic ranges.
authors: Center for Systems Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, Massachusetts 02114, USA.
authors: Changwook
authors: C
authors: Min
authors: Huilin
authors: H
authors: Shao
authors: Monty
authors: M
authors: Liong
authors: Tae-Jong
authors: TJ
authors: Yoon
authors: Ralph
authors: R
authors: Weissleder
authors: Hakho
authors: H
authors: Lee
mesh_terms: D003198:Computer Simulation; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D008422:Materials Testing; D008956:Models, Chemical
chemical_list: D058185:Magnetite Nanoparticles