@misc{BreitensteinHoelzelBier2010,
  author    = {Breitenstein, Michael and H{\"o}lzel, Ralph and Bier, Frank Fabian},
  title     = {Immobilization of different biomolecules by atomic force microscopy},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  number    = {872},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-43507},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435075},
  pages     = {9},
  year      = {2010},
  abstract  = {Background Micrometer resolution placement and immobilization of probe molecules is an important step in the preparation of biochips and a wide range of lab-on-chip systems. Most known methods for such a deposition of several different substances are costly and only suitable for a limited number of probes. In this article we present a flexible procedure for simultaneous spatially controlled immobilization of functional biomolecules by molecular ink lithography. Results For the bottom-up fabrication of surface bound nanostructures a universal method is presented that allows the immobilization of different types of biomolecules with micrometer resolution. A supporting surface is biotinylated and streptavidin molecules are deposited with an AFM (atomic force microscope) tip at distinct positions. Subsequent incubation with a biotinylated molecule species leads to binding only at these positions. After washing streptavidin is deposited a second time with the same AFM tip and then a second biotinylated molecule species is coupled by incubation. This procedure can be repeated several times. Here we show how to immobilize different types of biomolecules in an arbitrary arrangement whereas most common methods can deposit only one type of molecules. The presented method works on transparent as well as on opaque substrates. The spatial resolution is better than 400 nm and is limited only by the AFM's positional accuracy after repeated z-cycles since all steps are performed in situ without moving the supporting surface. The principle is demonstrated by hybridization to different immobilized DNA oligomers and was validated by fluorescence microscopy. Conclusions The immobilization of different types of biomolecules in high-density microarrays is a challenging task for biotechnology. The method presented here not only allows for the deposition of DNA at submicrometer resolution but also for proteins and other molecules of biological relevance that can be coupled to biotin.},
  language  = {en}
}
@article{BreitensteinNielsenHoelzeletal.2011,
  author    = {Breitenstein, Michael and Nielsen, Peter E. and H{\"o}lzel, Ralph and Bier, Frank Fabian},
  title     = {DNA-nanostructure-assembly by sequential spotting},
  series = {Journal of nanobiotechnology},
  volume    = {9},
  journal   = {Journal of nanobiotechnology},
  number    = {11},
  publisher = {BioMed Central},
  address   = {London},
  issn      = {1477-3155},
  doi       = {10.1186/1477-3155-9-54},
  pages     = {10},
  year      = {2011},
  abstract  = {Background: The ability to create nanostructures with biomolecules is one of the key elements in nanobiotechnology. One of the problems is the expensive and mostly custom made equipment which is needed for their development. We intended to reduce material costs and aimed at miniaturization of the necessary tools that are essential for nanofabrication. Thus we combined the capabilities of molecular ink lithography with DNA-self-assembling capabilities to arrange DNA in an independent array which allows addressing molecules in nanoscale dimensions. Results: For the construction of DNA based nanostructures a method is presented that allows an arrangement of DNA strands in such a way that they can form a grid that only depends on the spotted pattern of the anchor molecules. An atomic force microscope (AFM) has been used for molecular ink lithography to generate small spots. The sequential spotting process allows the immobilization of several different functional biomolecules with a single AFM-tip. This grid which delivers specific addresses for the prepared DNA-strand serves as a two-dimensional anchor to arrange the sequence according to the pattern. Once the DNA-nanoarray has been formed, it can be functionalized by PNA (peptide nucleic acid) to incorporate advanced structures. Conclusions: The production of DNA-nanoarrays is a promising task for nanobiotechnology. The described method allows convenient and low cost preparation of nanoarrays. PNA can be used for complex functionalization purposes as well as a structural element.},
  language  = {en}
}
@misc{BreitensteinNielsenHoelzeletal.2011,
  author    = {Breitenstein, Michael and Nielsen, Peter E. and H{\"o}lzel, Ralph and Bier, Frank Fabian},
  title     = {DNA-nanostructure-assembly by sequential spotting},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1027},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-43110},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431108},
  pages     = {12},
  year      = {2011},
  abstract  = {Background: The ability to create nanostructures with biomolecules is one of the key elements in nanobiotechnology. One of the problems is the expensive and mostly custom made equipment which is needed for their development. We intended to reduce material costs and aimed at miniaturization of the necessary tools that are essential for nanofabrication. Thus we combined the capabilities of molecular ink lithography with DNA-self-assembling capabilities to arrange DNA in an independent array which allows addressing molecules in nanoscale dimensions. Results: For the construction of DNA based nanostructures a method is presented that allows an arrangement of DNA strands in such a way that they can form a grid that only depends on the spotted pattern of the anchor molecules. An atomic force microscope (AFM) has been used for molecular ink lithography to generate small spots. The sequential spotting process allows the immobilization of several different functional biomolecules with a single AFM-tip. This grid which delivers specific addresses for the prepared DNA-strand serves as a two-dimensional anchor to arrange the sequence according to the pattern. Once the DNA-nanoarray has been formed, it can be functionalized by PNA (peptide nucleic acid) to incorporate advanced structures. Conclusions: The production of DNA-nanoarrays is a promising task for nanobiotechnology. The described method allows convenient and low cost preparation of nanoarrays. PNA can be used for complex functionalization purposes as well as a structural element.},
  language  = {en}
}
@misc{StankeWengerBieretal.2017,
  author    = {Stanke, S. and Wenger, C. and Bier, Frank Fabian and H{\"o}lzel, Ralph},
  title     = {Dielectrophoretic functionalization of nanoelectrode arrays for the detection of influenza viruses},
  series = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  volume    = {46},
  journal   = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  publisher = {Springer},
  address   = {New York},
  issn      = {0175-7571},
  pages     = {S337 -- S337},
  year      = {2017},
  language  = {en}
}
@misc{KniggeWengerBieretal.2017,
  author    = {Knigge, Xenia and Wenger, C. and Bier, Frank Fabian and H{\"o}lzel, Ralph},
  title     = {AC electrokinetic immobilisation of nanoobjects as individual singles in regular arrays},
  series = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  volume    = {46},
  journal   = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  publisher = {Springer},
  address   = {New York},
  issn      = {0175-7571},
  pages     = {S187 -- S187},
  year      = {2017},
  language  = {en}
}
@misc{LauxGibbonsErmilovaetal.2017,
  author    = {Laux, Eva-Maria and Gibbons, J. and Ermilova, Elena and Bier, Frank Fabian and H{\"o}lzel, Ralph},
  title     = {Broadband dielectric spectroscopy of bovine serum albumin in the GHz range},
  series = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  volume    = {46},
  journal   = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  publisher = {Springer},
  address   = {New York},
  issn      = {0175-7571},
  pages     = {S347 -- S347},
  year      = {2017},
  language  = {en}
}
@misc{LauxKniggeWengeretal.2017,
  author    = {Laux, Eva-Maria and Knigge, Xenia and Wenger, C. and Bier, Frank Fabian and H{\"o}lzel, Ralph},
  title     = {AC electrokinetic manipulation of nanoparticles and molecules},
  series = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  volume    = {46},
  journal   = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  publisher = {Springer},
  address   = {New York},
  issn      = {0175-7571},
  pages     = {S189 -- S189},
  year      = {2017},
  language  = {en}
}
@misc{LauxDocoslisWengeretal.2017,
  author    = {Laux, Eva-Maria and Docoslis, A. and Wenger, C. and Bier, Frank Fabian and H{\"o}lzel, Ralph},
  title     = {Combination of dielectrophoresis and SERS for bacteria detection and characterization},
  series = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  volume    = {46},
  journal   = {European biophysics journal : with biophysics letters ; an international journal of biophysics},
  publisher = {Springer},
  address   = {New York},
  issn      = {0175-7571},
  pages     = {S331 -- S331},
  year      = {2017},
  language  = {en}
}
@article{LauxErmilovaPannwitzetal.2018,
  author    = {Laux, Eva-Maria and Ermilova, Elena and Pannwitz, Daniel and Gibbons, Jessica and H{\"o}lzel, Ralph and Bier, Frank Fabian},
  title     = {Dielectric Spectroscopy of Biomolecules up to 110 GHz},
  series = {Frequenz},
  volume    = {72},
  journal   = {Frequenz},
  number    = {3-4},
  publisher = {De Gruyter},
  address   = {Berlin},
  issn      = {0016-1136},
  doi       = {10.1515/freq-2018-0010},
  pages     = {135 -- 140},
  year      = {2018},
  abstract  = {Radio-frequency fields in the GHz range are increasingly applied in biotechnology and medicine. In order to fully exploit both their potential and their risks detailed information about the dielectric properties of biological material is needed. For this purpose a measuring system is presented that allows the acquisition of complex dielectric spectra over 4 frequency decade up to 110 GHz. Routines for calibration and for data evaluation according to physicochemical interaction models have been developed. The frequency dependent permittivity and dielectric loss of some proteins and nucleic acids, the main classes of biomolecules, and of their sub-units have been determined. Dielectric spectra are presented for the amino acid alanine, the proteins lysozyme and haemoglobin, the nucleotides AMP and ATP, and for the plasmid pET-21, which has been produced by bacterial culture. Characterisation of a variety of biomolecules is envisaged, as is the application to studies on protein structure and function.},
  language  = {en}
}
@article{LauxBierHoelzel2018,
  author    = {Laux, Eva-Maria and Bier, Frank Fabian and H{\"o}lzel, Ralph},
  title     = {Dielectrophoretic Stretching of DNA},
  series = {DNA Nanotechnology},
  journal   = {DNA Nanotechnology},
  edition   = {2},
  publisher = {Humana Press Inc.},
  address   = {New York},
  isbn      = {978-1-4939-8582-1},
  issn      = {1064-3745},
  doi       = {10.1007/978-1-4939-8582-1_14},
  pages     = {199 -- 208},
  year      = {2018},
  abstract  = {The spatial control of DNA and of self-assembled DNA constructs is a prerequisite for the preparation of DNA-based nanostructures and microstructures and a useful tool for studies on single DNA molecules. Here we describe a protocol for the accumulation of dissolved lambda-DNA molecules between planar microelectrodes by the action of inhomogeneous radiofrequency electric fields. The resulting AC electrokinetic forces stretch the DNA molecules and align them parallel to the electric field. The electrode preparation from off-the-shelf electronic components is explained, and a detailed description of the electronic setup is given. The experimental procedure is controlled in real-time by fluorescence microscopy.},
  language  = {en}
}