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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 11: Poster: New Instruments and Methods

CPP 11.7: Poster

Montag, 22. März 2010, 16:30–18:00, Poster C

Micro total analysis system: A combination of a magnetic ratchet with giant magnetoresistance sensors — •Alexander Auge, Thomas Weiß, Dieter Akemeier, Frank Wittbracht, Alexander Weddemann, and Andreas Hütten — Uni Bielefeld, Fakultät für Physik, Universitätsstr. 25, 33615 Bielefeld, Germany

Micro Total Analysis Systems (µ TAS) on microfluidic chips is a rapidly growing field due to the large variety of possible applications like point of care diagnostics. The aim of µ TAS is to integrate all laboratory tasks on one microfluidic chip. These tasks include sample preparation, injection, manipulation, reaction, separation and detection. In this area the use of magnetic markers like beads or nanoparticles has gained importance. These markers can be selectively functionalized so that they can be attached to a variety of bioconjugates and provide reaction sites for chemical binding. One possible idea to transport, separate and detect magnetic beads is the ratchet concept. The basic idea of a ratchet is to use diffusion and a fluctuating asymmetric potential to move the magnetic markers. In this work, the ratchet is realized via a spatially periodic array of conducting lines and a magnetic out-of-plane field to create the asymmetric potential. Giant magnetoresistance sensors are placed in the potential minima of the ratchet leading to the possibility of bead detection; this allows an integrated analysis of the bead velocity. Since the bead velocity is size dependent, this enables drawing conclusions regarding e.g. bead-bacteria bindings.