We demonstrate the fabrication of nanoelectromagnets and the magnetic capture of a single magnetic nanoparticle. The magnetic nanoparticles are extracted from magnetotactic bacteria and their diameter is approximately 50 nm. We show that a single nanoparticle is captured at each corner of the serpentine-shaped nanoelectromagnet, and the maximum magnetic field of 35 mT (and the maximum magnetic-field gradient of 4× 105 Tm) is shown to be created at the capture spots of the nanoelectromagnet. It is also shown that there is a crossover between the magnetic force and the diffusion force at several hundred nm away from the magnet. This distance is comparable to the average interparticle distance.
Bibliographical noteFunding Information:
This work was supported by the Korean Ministry of Science and Technology through the Creative Research Initiative Program under Contract No. R16-1998-009-01001-0. The work at Korea University was supported by the Brain Korea 21 Project in 2004.