We demonstrate room temperature detection of single 20 nm super-paramagnetic nanoparticles (SPNs) with a wide-field optical microscope platform suitable for biological integration. The particles are made of magnetite (Fe3O4) and are thus non-toxic and biocompatible. Detection is accomplished via optically detected magnetic resonance imaging using nitrogen-vacancy defect centers in diamond, resulting in a DC magnetic field detection limit of 2.3 {\mu}T. This marks a large step forward in the detection of SPNs, and we expect that it will allow for the development of magnetic-field-based biosensors capable of detecting a single molecular binding event.
@article{arxiv.1403.0866,
title = {Room-temperature detection of single 20 nm super-paramagnetic nanoparticles with an imaging magnetometer},
author = {Michael Gould and Russell Barbour and Nicole Thomas and Hamed Arami and Kannan M. Krishnan and Kai-Mei Fu},
journal= {arXiv preprint arXiv:1403.0866},
year = {2015}
}
Comments
12 pages, 3 figures, submitted to Applied Physics Letters