Title | Bio-functionalization of monodisperse magnetic nanoparticles and their use as biomolecular labels in a magnetic tunnel junction based sensor. |
Publication Type | Journal Article |
Year of Publication | 2005 |
Authors | Grancharov SG, Zeng H, Sun S, Wang SX, O'Brien S, Murray CB, Kirtley JR, Held GA |
Journal | J Phys Chem B |
Volume | 109 |
Issue | 26 |
Pagination | 13030-5 |
Date Published | 2005 Jul 7 |
ISSN | 1520-6106 |
Keywords | Avidin, 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. |
DOI | 10.1021/jp051098c |
Alternate Journal | J Phys Chem B |
PubMed ID | 16852617 |