Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses IZI-BB
Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses IZI-BB

PD Dr. Ralph Hölzel

heads the Department of Biosystems Integration and Process Automation and the Working Group for Biomolecular Nanostructures and Metrology

 

© Fraunhofer IZI-BB, Foto: R. Hölzel

Scientific focus and expertise:

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Ralph Hölzel - ORCID: 0000-0002-0529-9174
  • Kruse, M., Altattan, B., Laux, E.-M., Grasse, N., Heinig, L., Möser, C., Smith, D. M., & Hölzel, R. (2022). Characterization of binding interactions of SARS-CoV-2 spike protein and DNA-peptide nanostructures. Scientific Reports, 12(1), 12828. https://doi.org/10.1038/s41598-022-16914-9
  • Kruse, M., Möser, C., Smith, D. M., Müller‐Landau, H., Rant, U., Hölzel, R., & Bier, F. F. (2022). Measuring Influenza A Virus and Peptide Interaction Using Electrically Controllable DNA Nanolevers. Advanced Materials Technologies, 7(5), 2101141. https://doi.org/10.1002/admt.202101141
  • Prüfer, M., Wenger, C., Bier, F. F., Laux, E.-M., & Hölzel, R. (2022). Activity of AC electrokinetically immobilized horseradish peroxidase. Electrophoresis, 43(18-19), 1920–1933. https://doi.org/10.1002/elps.202200073
  • Stanke, S., Wenger, C., Bier, F. F., & Hölzel, R. (2022). Ac electrokinetic immobilization of influenza virus. Electrophoresis, 43(12), 1309–1321. https://doi.org/10.1002/elps.202100324
  • Laux, E.-M., Knigge, X., Bier, F. F., Wenger, C., & Hölzel, R. (2016). Aligned Immobilization of Proteins Using AC Electric Fields. Small (Weinheim an Der Bergstrasse, Germany), 12(11), 1514–1520. https://doi.org/10.1002/smll.201503052
  • Laux, E.-M., Knigge, X., Bier, F. F., Wenger, C., & Hölzel, R. (2015). Dielectrophoretic immobilization of proteins: Quantification by atomic force microscopy. Electrophoresis, 36(17), 2094–2101. https://doi.org/10.1002/elps.201500108
  • Laux, E.-M., Knigge, X., Otto S., Wenger C., Bier F.F. & Hölzel R. (2015) Nano-manipulation of proteins by AC electric fields. Eur. Biophys. J. 44, 58
  • Ermilova, E., Bier, F. F., & Hölzel, R. (2014). Dielectric measurements of aqueous DNA solutions up to 110 GHz. Physical Chemistry Chemical Physics : PCCP, 16(23), 11256–11264. https://doi.org/10.1039/c3cp55272a
  • (2014, March 3–6). Label-free Immobilization of Nano-particles on Silicon based Electrodes for Single-biomolecule Studies. In Proceedings of the International Conference on Biomedical Electronics and Devices (pp. 176–180). SCITEPRESS - Science and and Technology Publications. https://doi.org/10.5220/0004888101760180
  • Füllbrandt, M., Ermilova, E., Asadujjaman, A., Hölzel, R., Bier, F. F., Klitzing, R. von, & Schönhals, A. (2014). Dynamics of linear poly(N-isopropylacrylamide) in water around the phase transition investigated by dielectric relaxation spectroscopy. The Journal of Physical Chemistry. B, 118(13), 3750–3759. https://doi.org/10.1021/jp501325x
  • Laux, E.-M., Kaletta, U. C., Bier, F. F., Wenger, C., & Hölzel, R. (2014). Functionality of dielectrophoretically immobilized enzyme molecules. Electrophoresis, 35(4), 459–466. https://doi.org/10.1002/elps.201300447
  • Otto, S., Kaletta, U., Bier, F. F., Wenger, C., & Hölzel, R. (2014). Dielectrophoretic immobilisation of antibodies on microelectrode arrays. Lab on a Chip, 14(5), 998–1004. https://doi.org/10.1039/C3LC51190A
  • Linck, L., Reiß, E., Bier, F., & Resch-Genger, U. (2012). Direct labeling rolling circle amplification as a straightforward signal amplification technique for biodetection formats. Analytical Methods, 4(5), 1215. https://doi.org/10.1039/C2AY05760C
  • Breitenstein, M., Nielsen, P. E., Hölzel, R., & Bier, F. F. (2011). Dna-nanostructure-assembly by sequential spotting. Journal of Nanobiotechnology, 9, 54. https://doi.org/10.1186/1477-3155-9-54
  • Reiss, E., Hölzel, R., & Bier, F. F. (2011). Preparation of DNA nanostructures with repetitive binding motifs by rolling circle amplification. Methods in Molecular Biology (Clifton, N.J.), 749, 151–168. https://doi.org/10.1007/978-1-61779-142-0_11
  • Stanke, S., Bier, F. F., & Hölzel, R. (2011). Fluid streaming above interdigitated electrodes in dielectrophoresis experiments. Electrophoresis, 32(18), 2448–2455. https://doi.org/10.1002/elps.201100096
  • Breitenstein, M., Hölzel, R., & Bier, F. F. (2010). Immobilization of different biomolecules by atomic force microscopy. Journal of Nanobiotechnology, 8, 10. https://doi.org/10.1186/1477-3155-8-10
  • Henning, A., Bier, F. F., & Hölzel, R. (2010). Dielectrophoresis of DNA: Quantification by impedance measurements. Biomicrofluidics, 4(2). https://doi.org/10.1063/1.3430550

  • Bier F, Hölzel R. Method and device for directed immobilisation of nano-and micro-objects on a substrate surface, immobilisates obtained thereby, and use thereof. EP 12 775 135.2 Priority 15.11.2011

Thermal image of a photodetector board
© Fraunhofer IZI-BB, R. Hölzel
Thermal image of a photodetector board
  • High-resolution lateral structuring of immobilized materials ("nanostructures")
  • Construction of two- and three-dimensional nanostructures by controlled self-assembly of biological macromolecules (DNA, proteins)
  • Direct printing and writing of nanoscale structures using atomic force microscope and molecular ink
  • Establishment of nanotechnology with biomolecules; single molecule anchoring
  • Development of nanoarrays for single cell investigation
  • Impedance spectroscopy on biomolecules
  • Spatial manipulation of molecules by alternating electric fields (molecular dielectrophoresis)