| 1. |
- Feifel, Sven C., et al.
(author)
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Catalytically Active Silica Nanoparticle-Based Supramolecular Architectures of Two Proteins - Cellobiose Dehydrogenase and Cytochrome c on Electrodes
- 2012
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In: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 28:25, s. 9189-9194
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Journal article (peer-reviewed)abstract
- Artificial nanobiomolecular architectures that follow natural examples in protein assembly become more and more important from basic and applied points of view. Our study describes the investigation on cellobiose dehydrogenase (CDH), cytochrome c (cyt c), and silica nanoparticles (SiNP's) for the construction of fully catalytically active supramolecular architectures on electrodes. We report on intraprotein, interprotein, and direct electron-transfer reaction cascades of cellobiose dehydrogenase and cytochrome c immobilized in multiple supramolecular layers. Carboxy-modified SiNP's are used to provide an artificial matrix, which enables protein arrangement in an electroactive form. Direct and interprotein electron transfer has been established for a two-protein system with CDH and cyt c in a layered architecture for the first time. We also highlight that the glycosylation of CDH and the silica nanoparticle size play key roles in the mode of operation in such a complex system. The response of the specific substrate, here lactose, can be tuned by the number of immobilized nanobiomolecular layers.
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| 2. |
- Feifel, Sven C., et al.
(author)
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Electrocatalytically active multi-protein assemblies using nanoscaled building blocks
- 2013
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In: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 3:10, s. 3428-3437
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Journal article (peer-reviewed)abstract
- Biosensors based on nanomaterials constitute an emerging area of interdisciplinary research. In particular in electrochemical sensors, electron transfer cascades can be used for defined signal generation. Our study describes the investigation of silica nanoparticles (SiNPs), DNA, cytochrome c (cyt c) and cellobiose dehydrogenase (CDH) for the development of catalytically active multi-protein assemblies. We report on direct and interprotein electron transfer reaction cascades of CDH and cyt c in an immobilized form by means of nanoscaled building blocks: Carboxy-modified SiNPs, and DNA. The building blocks provide an artificial matrix, which permit protein arrangement in an electro- and catalytically-active form. Multilayered protein architectures on electrodes featuring direct and interprotein electron transfer by the use of entirely different nanoscaled building blocks has been established for the first time. In addition we highlight, that the secondary building blocks (DNA or SiNPs) used for the construction as well as the glycosylation of the enzyme (CDH) play a key role for the mode of operation in such complex entities.
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| 3. |
- Renneberg, Reinhard, et al.
(author)
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Frieder scheller and the short history of biosensors
- 2008
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In: Advances in Biochemical Engineering/Biotechnology. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 0724-6145 .- 1616-8542. - 9783540752004 ; 109, s. 1-18
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Journal article (other academic/artistic)abstract
- This is a first attempt at a brief sketch of the history of biosensors. It is far from complete and rather unsystematic. Many names are still missing, and we apologize for this. But the authors hope to have laid a humble cornerstone for a future "Complete History of Biosensors". We hope that many of our colleagues will contribute!
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| 4. |
- Salieb-Beugelaar, Georgette, et al.
(author)
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Field-Dependent DNA Mobility in 20 nm High Nanoslits.
- 2008
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In: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 8:7, s. 1785-1790
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Journal article (peer-reviewed)abstract
- The transport behavior of lambda-DNA (48 kbp) in fused silica nanoslits is investigated upon application of electrical fields of different strengths. The slit dimensions are 20 nm in height, 3 microm in width, and 500 microm in length. With fields of 30 kV/m or below, the molecules move fluently through the slits, while at higher electrical fields, the DNA molecules move intermittently, resulting in a strongly reduced mobility. We propose that the behavior can be explained by mechanical and/or field-induced dielectrophoretic DNA trapping due to the surface roughness in the nanoslits. The observation of preferential pathways and trapping sites of the lambda-DNA molecules through the nanoslits supports this hypothesis and indicates that the classical viscous friction models to explain the DNA movement in nanoslits needs to be modified to include these effects. Preliminary experiments with the smaller XbaI-digested litmus-DNA (2.8 kbp) show that the behavior is size-dependent, suggesting that the high field electrophoresis in nanoslits can be used for DNA separation.
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| 5. |
- Sarauli, David, et al.
(author)
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Investigation of the mediated electron transfer mechanism of cellobiose dehydrogenase at cytochrome c-modified gold electrodes
- 2012
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In: Bioelectrochemistry. - : Elsevier BV. - 1878-562X .- 1567-5394. ; 87, s. 9-14
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Journal article (peer-reviewed)abstract
- The present study reports on the comparison of direct and mediated electron transfer pathways in the interaction of the fungal enzyme cellobiose dehydrogenase (CDH) with the redox protein cytochrome c (cyt c) immobilised at a modified gold electrode surface. Two types of CDHs were chosen for this investigation: a basidiomycete (white rot) CDH from Trametes villosa and a recently discovered ascomycete from the thermophilic fungus Corynascus thermophilus. The choice was based on the pH-dependent interaction of these enzymes with cyt c in solution containing the substrate cellobiose (CB). Both enzymes show rather similar catalytic behaviour at lower pH, dominated by a direct electron exchange with the electrode. With increasing pH, however, also cyt c-mediated electron transfer becomes possible. The pH-dependent behaviour in the presence and in the absence of cyt c is analysed and the potential reaction mechanism for the two enzymes with a different pH-behaviour is discussed. (c) 2011 Published by Elsevier B.V.
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