Selective detection of magnetic nanoparticles in biomedical applications using differential magnetometry

M. Visscher, Sebastiaan Waanders, Hendrikus J.G. Krooshoop, Bernard ten Haken

Research output: Contribution to journalArticleAcademicpeer-review

12 Citations (Scopus)
3 Downloads (Pure)

Abstract

The present study describes a new concept of magnetic detection that can be used for fast, selective measurements on magnetic nanoparticles and which is not influenced by the presence of materials with a linear magnetic susceptibility, like tissue. Using an alternating excitation field (View the MathML sourcef~5kHz) with a sequence of static offset fields, the magnetometer is selectively sensitive for the nonlinear properties of magnetic nanoparticles in samples. The offset field sequence modulates the measured inductive response of nonlinear magnetic materials, in contrast to linear magnetic materials. We demonstrate a detection limit for superparamagnetic iron oxide nanoparticles in the sub-microgram (iron) range. The mass sensitivity of the procedure increases with offset field amplitude and particle size. Compared to the sensitivity for particles in suspension, the sensitivity reduces for particles accumulated in lymph node tissue or immobilized by drying, which is attributed to a change in Brownian relaxation. The differential magnetometry concept is used as a tool to perform non-destructive analysis of magnetic nanoparticles in clinically relevant tissue samples at room temperature. In addition, the differential magnetometer can be used for fundamental quantitative research of the performance of magnetic nanoparticles in alternating fields. The method is a promising approach for in vivo measurements during clinical interventions, since it suppresses the linear contribution of the surrounding body volume and effectively picks out the nonlinear contribution of magnetic tracer.
Original languageEnglish
Pages (from-to)31-39
JournalJournal of magnetism and magnetic materials
Volume365
Issue numberSeptember 2014
DOIs
Publication statusPublished - 2014

Keywords

  • METIS-309504
  • IR-94647

Fingerprint Dive into the research topics of 'Selective detection of magnetic nanoparticles in biomedical applications using differential magnetometry'. Together they form a unique fingerprint.

Cite this