title: Manipulation of Superparamagnetic Beads on Patterned Exchange-Bias Layer Systems for Biosensing Applications.
abstract: A technology platform based on a remotely controlled and stepwise transport of an array arrangement of superparamagnetic beads (SPB) for efficient molecular uptake, delivery and accumulation in the context of highly specific and sensitive analyte molecule detection for the application in lab-on-a-chip devices is presented. The near-surface transport of SPBs is realized via the dynamic transformation of the SPBs' magnetic potential energy landscape above a magnetically stripe patterned Exchange-Bias (EB) thin film layer systems due to the application of sub-mT external magnetic field pulses. In this concept, the SPB velocity is dramatically influenced by the magnitude and gradient of the magnetic field landscape (MFL) above the magnetically stripe patterned EB substrate, the SPB to substrate distance, the magnetic properties of both the SPBs and the EB layer system, respectively, as well as by the properties of the external magnetic field pulses and the surrounding fluid. The focus of this review is laid on the specific MFL design in EB layer systems via light-ion bombardment induced magnetic patterning (IBMP). A numerical approach is introduced for the theoretical description of the MFL in comparison to experimental characterization via scanning Hall probe microscopy. The SPB transport mechanism will be outlined in terms of the dynamic interplay between the EB substrate's MFL and the pulse scheme of the external magnetic field.
authors.affiliation: Institute of Physics and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, Heinrich-Plett-Str.40, Kassel D-34132, Germany. ehresmann@physik.uni-kassel.de.
authors.forename: Arno
authors.initials: A
authors.lastname: Ehresmann
authors.affiliation: Institute of Physics and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, Heinrich-Plett-Str.40, Kassel D-34132, Germany. iris.koch@physik.uni-kassel.de.
authors.forename: Iris
authors.initials: I
authors.lastname: Koch
authors.affiliation: Institute of Physics and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, Heinrich-Plett-Str.40, Kassel D-34132, Germany. holzinger@uni-kassel.de.
authors.forename: Dennis
authors.initials: D
authors.lastname: Holzinger
mesh_terms: D015374:Biosensing Techniques; D008280:Magnetics; D059346:Magnets; D046210:Microfluidic Analytical Techniques; D036103:Nanotechnology
keywords: DOWMAT; Exchange-Bias; biosensor; ion bombardment induced magnetic patterning (IBMP); magnetic field landscape design; magnetic stray fields; microfluid mixing; particle transport; potential energy landscape; scanning Hall probe microscopy; superparamagnetic bead