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Bio-functionalization of monodisperse magnetic nanoparticles and their use as biomolecular labels in a magnetic tunnel junction based sensor.

TitleBio-functionalization of monodisperse magnetic nanoparticles and their use as biomolecular labels in a magnetic tunnel junction based sensor.
Publication TypeJournal Article
Year of Publication2005
AuthorsGrancharov SG, Zeng H, Sun S, Wang SX, O'Brien S, Murray CB, Kirtley JR, Held GA
JournalJ Phys Chem B
Volume109
Issue26
Pagination13030-5
Date Published2005 Jul 7
ISSN1520-6106
KeywordsAvidin, Biosensing Techniques, Biotin, DNA, Single-Stranded, Ferric Compounds, Magnetics, Manganese, Nanoparticles, Nucleic Acid Hybridization, Silicon Dioxide
Abstract

Monodisperse magnetic nanoparticles (NPs) could enable the ultra-sensitive magnetic detection of biological analytes. However, rendering these particles biocompatible has remained a challenge. We report the bio-functionalization and detection of 12-nm manganese ferrite NPs. We have achieved the site-specific binding of biotin-functionalized NPs onto avidin-patterned silicon oxide substrates and DNA-functionalized NPs onto complementary DNA-patterned silicon oxide substrates. Utilizing scanning SQUID microscopy, we show that these substrate-bound NPs retain their magnetic properties. Finally, we demonstrate a novel method of detecting either protein binding or DNA hybridization at room temperature using the NPs and a magnetic tunnel-junction-based biosensor situated in orthogonal magnetic fields.

DOI10.1021/jp051098c
Alternate JournalJ Phys Chem B
PubMed ID16852617