Magnetorelaxometry of magnetic nanoparticles in magnetically unshielded environment utilizing a differential fluxgate arrangement

摘要

A magnetorelaxometry system based on a differential fluxgate arrangement is presented. Compared to the single fluxgate setup, the use of two fluxgate magnetometers increases the relaxation signal from the sample by a factor of 2, the signal-to-noise ratio by a factor root 2, and allows one to perform magnetorelaxation measurements without any magnetic shielding. For a sample with superparamagnetic Fe3O4 nanoparticles and a volume of 150 mu l, 100 nmol Fe could be detected, limited by the intrinsic noise of the fluxgate sensors. (c) 2005 American Institute of Physics.