Berlin 2018 – scientific programme
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BP: Fachverband Biologische Physik
BP 9: Postersession I
BP 9.13: Poster
Monday, March 12, 2018, 17:30–19:30, Poster A
Dielectrophoretic Immobilization of Nanoobjects as Singles — •Xenia Knigge1, Christian Wenger2, Frank F. Bier1, and Ralph Hölzel1 — 1Fraunhofer Institute for Cell Therapy and Immunology IZI, Branch Bioanalysis and Bioprocesses, Potsdam (IZI-BB), Germany. — 2IHP GmbH - Leibniz Institute for Innovative Microelectronics, Frankfurt (Oder), Germany.
For the construction of a biosensor the immobilization of the bioreceptor is a key element. Here we demonstrate the immobilization of fluorescently labeled nanospheres as a model system applying dielectrophoresis (DEP). DEP is a phenomenon in which a dipole is induced in a polarizable particle in an inhomogeneous AC electric field. By the right choice of frequency, this particle can be moved and immobilized. Also an alignment of the biomolecules is advantageous to get a strong signal, which is achieved by DEP. The nanoobjects have been immobilized as individual objects on electrodes of a regular array consisting of many thousands of vertical silicon or tungsten based nanoelectrodes. Immobilization and singling is proved by fluorescence microscopy in combination with scanning electron microscopy. Owing to the large number of electrodes being observed simultaneously, occupation numbers of submicroscopical particles could be determined with good statistics applying histograms. Occupation numbers and patterns were determined as a function of particle size (down to 50nm) and electrode diameter (50nm and 500nm).