PUB - Publikationen an der Universität Bielefeld

Fast continuous flow detection of biomolecules in lab-on-a-chip structures is a challenging task. Combining these molecules with small magnetic particles, the interaction between their stray field and, e.g., magneto-resistive sensors can be used to indirectly prove the biomolecules. To position the particles on top of a sensor array at the bottom of the flow channel, we propose a microfluidic structure of changing channel height combining hydrodynamic and gravitational effects. We present numerical calculations predicting an increase in the capture rate by more than 100% in comparison to a straight channel. We experimentally realize an optical analysis of the specific binding of biotin-functionalized Chemagen beads on a streptavidin-coated surface. To prove the binding is not due to the surface effects, a second uncoated bead species is employed.