title: Aligned Immobilization of Proteins Using AC Electric Fields.
abstract: Protein molecules are aligned and immobilized from solution by AC electric fields. In a single-step experiment, the enhanced green fluorescent proteins are immobilized on the surface as well as at the edges of planar nanoelectrodes. Alignment is found to follow the molecules' geometrical shape with their longitudinal axes parallel to the electric field. Simultaneous dielectrophoretic attraction and AC electroosmotic flow are identified as the dominant forces causing protein movement and alignment. Molecular orientation is determined by fluorescence microscopy based on polarized excitation of the proteins' chromophores. The chromophores' orientation with respect to the whole molecule supports X-ray crystal data.
authors.affiliation: Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam-Golm, Germany.
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Laux
authors.affiliation: Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam-Golm, Germany.
authors.forename: Xenia
authors.initials: X
authors.lastname: Knigge
authors.affiliation: Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam-Golm, Germany.
authors.forename: Frank F
authors.initials: FF
authors.lastname: Bier
authors.affiliation: IHP GmbH-Leibniz Institute for Innovative Microelectronics, Im Technologiepark 25, 15235, Frankfurt/Oder, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Wenger
authors.affiliation: Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), Am Mühlenberg 13, 14476, Potsdam-Golm, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Hölzel
mesh_terms: D004560:Electricity; D004566:Electrodes; D049452:Green Fluorescent Proteins / Q000737:chemistry*; D055767:Immobilized Proteins / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D012996:Solutions
chemical_list: D055767:Immobilized Proteins; D012996:Solutions; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins
keywords: alternating current electroosmotic flow; dielectrophoresis; enhanced green fluorescent protein; molecular alignment; nanomanipulation