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| Substrate-free Biosensing using Brownian Rotation of Bio-conjugated Magnetic Nanoparticles |
| Journal of Magnetics, Volume 11, Number 4, 31 Dec 2006, Pages 189-194 |
| Seok-Hwan Chung(Materials Science Division), Axel Hoffmann(Materials Science Division), Liaohai Chen(Bioscience Division, Argonne National Laboratory), Shouheng Sun(Department of Chemistry, Brown University), Konstantin Guslienko(Materials Science Division), Marcos Grimsditch(Materials Science Division), Samuel D. Bader(Materials Science Division) |
| Abstract |
| The recent development of bio-conjugated magnetic nanoparticles offers many opportunities for applications in the field of biomedicine. In particular, the use of magnetic nanoparticles for biosensing has generated widespread research efforts following the progress of various magnetic field sensors. Here we demonstrate substrate-free biosensing approaches based on the Brownian rotation of ferromagnetic nanoparticles suspended in liquids. The signal transduction is through the measurement of the magnetic ac susceptibility as a function of frequency, whose peak position changes due to the modification of the hydrodynamic radius of bio-conjugated magnetic nanoparticles upon binding to target bio-molecules. The advantage of this approach includes its relative simplicity and integrity compared to methods that use substrate-based stray-field detectors. |
| Keywords: ac susceptibility; Brownian relaxation; magnetic nanoparticle; biomagnetic sensor |
| DOI: |
| Full Text: PDF |
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