TY - GEN A1 - Breitenstein, Michael A1 - Hölzel, Ralph A1 - Bier, Frank Fabian T1 - Immobilization of different biomolecules by atomic force microscopy T2 - Postprints der Universität Potsdam : Mathematisch Naturwissenschaftliche Reihe N2 - 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 872 KW - Atomic Force Microscope KW - Immobilization KW - Cross Contamination KW - Roth GmbH KW - Microcontact Printing Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435075 SN - 1866-8372 IS - 872 ER - TY - JOUR A1 - Rübsam, Kristin A1 - Stomps, Benjamin René Harald A1 - Böker, Alexander A1 - Jakob, Felix A1 - Schwaneberg, Ulrich T1 - Anchor peptides: A green and versatile method for polypropylene functionalization JF - Polymer : the international journal for the science and technology of polymers KW - Material binding peptides KW - Anchor peptides KW - Surface modification KW - Immobilization Y1 - 2017 U6 - https://doi.org/10.1016/j.polymer.2017.03.070 SN - 0032-3861 SN - 1873-2291 VL - 116 SP - 124 EP - 132 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Sarauli, David A1 - Xu, Chenggang A1 - Dietzel, Birgit A1 - Schulz, Burkhard A1 - Lisdat, Fred T1 - Differently substituted sulfonated polyanilines - the role of polymer compositions in electron transfer with pyrroloquinoline quinone-dependent glucose dehydrogenase JF - Acta biomaterialia N2 - Sulfonated polyanilines have become promising building blocks in the construction of biosensors, and therefore we use here differently substituted polymer forms to investigate the role of their structural composition and properties in achieving a direct electron transfer with the redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH). To this end, new copolymers containing different ratios of 2-methoxyaniline-5-sulfonic acid (MAS), 3-aminobenzenesulfonic acid (ABS) and 3-aminobenzoic acid (AB) units have been chemically synthesized. All polymers have been studied with respect to their ability to react directly with PQQ-GDH. This interaction has been monitored initially in solution, and subsequently on electrode surfaces. The results show that only copolymers with MAS and aniline units can directly react with PQQ-GDH in solution; the background can be mainly ascribed to the emeraldine salt redox state of the polymer, allowing rather easy reduction. However, when polymers and the enzyme are immobilized on the surface of carbon nanotube-containing electrodes, direct bioelectrocatalysis is also feasible in the case of copolymers composed of ABS/AB and MAS/AB units, existing initially in pernigraniline base form. This verifies that a productive interaction of the enzyme with differently substituted polymers is feasible when the electrode potential can be used to drive the reaction towards the oxidation of the substrate-reduced enzyme. These results clearly demonstrate that enzyme electrodes based on sulfonated polyanilines and direct bioelectrocatalysis can be successfully constructed. KW - Sulfonated polyaniline KW - PQQ-dependent glucose dehydrogenase KW - Direct electron transfer KW - Immobilization KW - Bioelectrocatalysis Y1 - 2013 U6 - https://doi.org/10.1016/j.actbio.2013.06.008 SN - 1742-7061 VL - 9 IS - 9 SP - 8290 EP - 8298 PB - Elsevier CY - Oxford ER - TY - JOUR A1 - Spricigo, Roberto A1 - Leimkühler, Silke A1 - Gorton, Lo A1 - Scheller, Frieder W. A1 - Wollenberger, Ursula T1 - The Electrically Wired Molybdenum Domain of Human Sulfite Oxidase is Bioelectrocatalytically Active JF - European journal of inorganic chemistry : a journal of ChemPubSoc Europe N2 - We report electron transfer between the catalytic molybdenum cofactor (Moco) domain of human sulfite oxidase (hSO) and electrodes through a poly(vinylpyridine)-bound [osmium(N,N'-methyl-2,2'-biimidazole)(3)](2+/3+) complex as the electron-transfer mediator. The biocatalyst was immobilized in this low-potential redox polymer on a carbon electrode. Upon the addition of sulfite to the immobilized separate Moco domain, the generation of a significant catalytic current demonstrated that the catalytic center is effectively wired and active. The bioelectrocatalytic current of the wired separate catalytic domain reached 25% of the signal of the wired full molybdoheme enzyme hSO, in which the heme b(5) is involved in the electron-transfer pathway. This is the first report on a catalytically active wired molybdenum cofactor domain. The formal potential of this electrochemical mediator is between the potentials of the two cofactors of hSO, and as hSO can occupy several conformations in the polymer matrix, it is imaginable that electron transfer from the catalytic site to the electrode through the osmium center occurs for the hSO molecules in which the Moco domain is sufficiently accessible. The observation of catalytic oxidation currents at low potentials is favorable for applications in bioelectronic devices. KW - Metalloenzymes KW - Enzyme catalysis KW - Immobilization KW - Osmium Y1 - 2015 U6 - https://doi.org/10.1002/ejic.201500034 SN - 1434-1948 SN - 1099-0682 IS - 21 SP - 3526 EP - 3531 PB - Wiley-VCH CY - Weinheim ER -