Magnetic nano-particles for biosensing applications
Master students: Lindy van Velzen, Carolien Lamers, Philip Somers
In the current magnetic biosensor nanometer-sized (100-1000 nm) superparamagnetic beads are used as labels. Knowledge on the magnetic properties of these particles is essential for detection as well as for field-assisted transport in the system. Magnetic characterization of the particles requires an individual particle approach, because strong differences between the particles can exist. We measure the susceptibility of individual particles using integrated current wires on a chip and an optical microscope, by observing either the speed of the particles (the well-known magnetophoresis technique) or the confined Brownian motion of the particles (a new technique that we developed, APL 2006).