Kolloquiumsvortrag: PD Dr. Hubert Brückl, Danube University Krems ÖSTERREICH
Kiel, Kaiserstraße 2, Gebäude D, Aquarium
Titel: "Magnetoresistive sensors and magnetic nanoparticles applied to biomolecular diagnostics"
Hubert Brückl, Center for Integrated Sensor Systems, Danube University Krems, Austria
Recent progress in fabrication and characterization of magnetic nano-objects like rods and beads has triggered possible applications in biomedical diagnostics. Magnetic nano-objects provide the unique possibility to actively manipulate biomolecules in solution and on-chip fluidic channels which paves the way to an integrated magnetic Lab-on-a-Chip combining detection and manipulation. Advancing this idea, a unique magnetic Lab-on-a-Bead is presented which is based on highly sensitive plasmon-optical detection of the rotational dynamics of anisotropic magnetic nanoparticles immersed in the sample solution. On the specific binding of analyte molecules to the antibody functionalized nanoparticle surfaces, their hydrodynamic volumes increase, which translates into a change in their rotational dynamics. A suitable nanoparticle type consists of an elongated core-shell structure with magnetic core and noble metal shell. Compared to existing nanoparticle-based homogeneous immunodiagnostic methods, this approach promises to combine ease of use, minimum sample preparation and a simple setup with femtomolar analyte sensitivity.
Additionally to the diagnostics, such magnetic Lab-on-a-Chip platforms are capable for on-chip cell analysis. Phagocytosis of human fibroblast (NHDF) and human prostate cancer (DU145) cells are studied in-vitro by magnetic beads. By varying bead size and surface modification as well as cell physiology (i.e. drug or metabolic inhibition), we mimic cellular responses to changes in the environment. Compared to existing end-point detection methods, this chip-based approach allows real-time measurements of the kinetics of cellular uptake mechanisms.