SKM 2023 – scientific programme

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MA: Fachverband Magnetismus

MA 40: Poster Magnetism II

MA 40.43: Poster

Thursday, March 30, 2023, 14:00–16:00, P2/EG

Characterizing the defocusing behaviour of magnetic microparticles for the application in three-dimensional trajectory tracking — •Nikolai Weidt, Rico Huhnstock, Yahya Shubbak, and Arno Ehresmann — Institute of Physics and Center for Interdisciplinary Nanostructure Science and Technology (CINSaT), University of Kassel, Heinrich-Plett-Str. 40, D-34132 Kassel

For the implementation in Lab-on-a-chip systems, superparamagnetic particles can be surface-functionalized to bind to specific analytes [1]. Making use of the transport of particles above magnetically stripe-patterned exchange bias layer systems is a promising approach to achieve a remote-controlled and directed transport of these particles [2]. The trajectories of particles during transport can be evaluated for detection of analyte binding events. To get access to the third dimension in optical microscopy, the image characteristics of particles moving out of the focal plane during transport steps are analyzed [3]. In this work quantization of defocusing is achieved by determining the Tenenbaum gradient of single particle images. Correlation between Tenenbaum gradient and the particle’s vertical position is established by moving the particles in z-direction through the focal plane of the microscope defined steps. Here we show Tenenbaum gradient curves for differently composed particles and changing illumination conditions. [1] Rampini et al. (2016) Lab on a Chip, 16(19), pp. 3645-3663. [2] Holzinger et al. (2015) ACS Nano, 9(7), pp. 7323-7331. [3] Tasadduq et al. (2015) Flow Measurement and Instrumentation, 45, pp. 218-224.