@article{WollenbergerLisdatScheller1997,
  author    = {Wollenberger, Ursula and Lisdat, Fred and Scheller, Frieder W.},
  title     = {Enzymatic substrade recycling electrodes},
  year      = {1997},
  language  = {en}
}
@article{WettsteinKanoSchaeferetal.2016,
  author    = {Wettstein, Christoph and Kano, Kenji and Schaefer, Daniel and Wollenberger, Ursula and Lisdat, Fred},
  title     = {Interaction of Flavin-Dependent Fructose Dehydrogenase with Cytochrome c as Basis for the Construction of Biomacromolecular Architectures on Electrodes},
  series = {Analytical chemistry},
  volume    = {88},
  journal   = {Analytical chemistry},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0003-2700},
  doi       = {10.1021/acs.analchem.6b00815},
  pages     = {6382 -- 6389},
  year      = {2016},
  abstract  = {The creation of electron transfer (ET) chains based on the defined arrangement of enzymes and redox proteins on electrode surfaces represents an interesting approach within the field of bioelectrocatalysis. In this study, we investigated the ET reaction of the flavin-dependent enzyme fructose dehydrogenase (FDH) with the redox protein cytochrome c (cyt c). Two different pH optima were found for the reaction in acidic and neutral solutions. When cyt c was adsorbed on an electrode surface while the enzyme remained in solution, ET proceeded efficiently in media of neutral pH. Interprotein ET was also observed in acidic media; however, it appeared to be less efficient. These findings suggest that two different ET pathways between the enzyme and cyt c may occur. Moreover, cyt c and FDH were immobilized in multiple layers on an electrode surface by means of another biomacromolecule: DNA (double stranded) using the layer -by -layer technique. The biprotein multilayer architecture showed a catalytic response in dependence on the fructose concentration, indicating that the ET reaction between both proteins is feasible even in the immobilized state. The electrode showed a defined response to fructose and a good storage stability. Our results contribute to the better understanding of the ET reaction between FDH and cyt c and provide the basis for the creation of all-biomolecule based fructose sensors the sensitivity of which can be controlled by the layer preparation.},
  language  = {en}
}
@article{WegerichTuranoAllegrozzietal.2009,
  author    = {Wegerich, Franziska and Turano, Paola and Allegrozzi, Marco and Moehwald, Helmuth and Lisdat, Fred},
  title     = {Cytochrome c mutants for superoxide biosensors},
  issn      = {0003-2700},
  doi       = {10.1021/Ac802571h},
  year      = {2009},
  abstract  = {The effect of introducing positive charges (lysines) in human cytochrome c (cyt c) on the redox properties and reaction rates of cyt c with superoxide radicals was studied. The mutated forms of this electron-transfer protein are used as sensorial recognition elements for the amperometric detection of the reactive oxygen radical. The proteins were prepared by site-directed mutagenesis focusing on amino acids near the heme edge. The 11 mutants of human cyt c expressed in the course of this research have been characterized by UV-vis spectroscopy, circular dichroism, and NMR spectroscopy to verify overall structure integrity as well as axial coordination of the heme iron. The mutants are investigated voltammetrically using promoter-modified gold electrodes with respect to redox activity and formal redox potential. The rate constants for the reaction with superoxide have been determined spectrophotometrically. Four mutants show a higher reaction rate with the radical as compared to the wild type. These mutants are used for the construction of superoxide sensors based on thiol-modified gold electrodes and covalently fixed proteins. We found that the E66K mutant-based electrode has a clearly higher sensitivity in comparison with the wild-type-based sensor while retaining the high selectivity and showing a good storage stability.},
  language  = {en}
}
@article{SzeponikMoellerPfeifferetal.1997,
  author    = {Szeponik, Jan and M{\"o}ller, B. and Pfeiffer, Dorothea and Lisdat, Fred and Wollenberger, Ursula and Makower, Alexander and Scheller, Frieder W.},
  title     = {Ultrasensitive bienzyme sensor for adrenaline},
  year      = {1997},
  language  = {en}
}
@article{SpricigoDronovLisdatetal.2009,
  author    = {Spricigo, Roberto and Dronov, Roman and Lisdat, Fred and Leimk{\"u}hler, Silke and Scheller, Frieder W. and Wollenberger, Ursula},
  title     = {Electrocatalytic sulfite biosensor with human sulfite oxidase co-immobilized with cytochrome c in a polyelectrolyte-containing multilayer},
  issn      = {1618-2642},
  doi       = {10.1007/s00216-008-2432-y},
  year      = {2009},
  abstract  = {An efficient electrocatalytic biosensor for sulfite detection was developed by co-immobilizing sulfite oxidase and cytochrome c with polyaniline sulfonic acid in a layer-by-layer assembly. QCM, UV-Vis spectroscopy and cyclic voltammetry revealed increasing loading of electrochemically active protein with the formation of multilayers. The sensor operates reagentless at low working potential. A catalytic oxidation current was detected in the presence of sulfite at the modified gold electrode, polarized at +0.1 V ( vs. Ag/AgCl 1 M KCl). The stability of the biosensor performance was characterized and optimized. A 17-bilayer electrode has a linear range between 1 and 60 mu M sulfite with a sensitivity of 2.19 mA M-1 sulfite and a response time of 2 min. The electrode retained a stable response for 3 days with a serial reproducibility of 3.8\% and lost 20\% of sensitivity after 5 days of operation. It is possible to store the sensor in a dry state for more than 2 months. The multilayer electrode was used for determination of sulfite in unspiked and spiked samples of red and white wine. The recovery and the specificity of the signals were evaluated for each sample.},
  language  = {en}
}
@article{SchellerWollenbergerWarsinkeetal.2001,
  author    = {Scheller, Frieder W. and Wollenberger, Ursula and Warsinke, Axel and Lisdat, Fred},
  title     = {Research and development in biosensors},
  year      = {2001},
  language  = {en}
}
@article{SchellerWollenbergerLeietal.2002,
  author    = {Scheller, Frieder W. and Wollenberger, Ursula and Lei, Chenghong and Jin, Wen and Ge, Bixia and Lehmann, Claudia and Lisdat, Fred and Fridman, Vadim},
  title     = {Bioelectrocatalysis by redox enzymes at modified electrodes},
  year      = {2002},
  language  = {en}
}
@article{SchellerPfeifferLisdatetal.1998,
  author    = {Scheller, Frieder W. and Pfeiffer, Dorothea and Lisdat, Fred and Bauer, Christian G. and Gajovic, Nenad},
  title     = {Enzyme biosensors based on oxygen detection},
  year      = {1998},
  language  = {en}
}
@article{SchellerLisdatWollenberger2005,
  author    = {Scheller, Frieder W. and Lisdat, Fred and Wollenberger, Ursula},
  title     = {Application of electrically contacted enzymes for biosensors},
  isbn      = {3-527- 30690-0},
  year      = {2005},
  language  = {en}
}
@article{SchellerJinEhrentreichFoersteretal.1999,
  author    = {Scheller, Frieder W. and Jin, Wen and Ehrentreich-F{\"o}rster, Eva and Ge, Bixia and Lisdat, Fred and B{\"u}ttemeyer, R. and Wollenberger, Ursula},
  title     = {Cytochrome c based superoxide sensor for in vivo application},
  year      = {1999},
  language  = {en}
}
@article{SarauliXuDietzeletal.2012,
  author    = {Sarauli, David and Xu, Chenggang and Dietzel, Birgit and Stiba, Konstanze and Leimk{\"u}hler, Silke and Schulz, Burkhard and Lisdat, Fred},
  title     = {Thin films of substituted polyanilines interactions with biomolecular systems},
  series = {Soft matter},
  volume    = {8},
  journal   = {Soft matter},
  number    = {14},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1744-683X},
  doi       = {10.1039/c2sm07261k},
  pages     = {3848 -- 3855},
  year      = {2012},
  abstract  = {We use substituted polyanilines for the construction of new polymer electrodes for interaction studies with the redox protein cytochrome c (cyt c) and the enzyme sulfite oxidase (SO). For these purposes four different polyaniline copolymers are chemically synthesized. Three of them are copolymers, containing 2-methoxyaniline-5-sulfonic acid with variable ratios of aniline; the fourth copolymer consists of 3-amino-benzoic acid and aniline. The results show that all polymers are suitable for being immobilized as thin stable films on gold wire and indium tin oxide (ITO) electrode surfaces from DMSO solution. This can be demonstrated by cyclic voltammetry and UV-Vis spectroscopy measurements. Moreover, cyt c can be electrochemically detected not only in solution, but also immobilized on top of the polymer films. Furthermore, the appearance of a significant catalytic current has been demonstrated for the sulfonated polyanilines, when the polymer-coated protein electrode is being measured upon addition of sulfite oxidase, confirming the establishment of a bioanalytical signal chain. Best results have been obtained for the polymer with highest sulfonation grade. The redox switching of the polymer by the enzymatic reaction can also be analyzed by following the spectral properties of the polymer electrode.},
  language  = {en}
}
@article{SarauliXuDietzeletal.2013,
  author    = {Sarauli, David and Xu, Chenggang and Dietzel, Birgit and Schulz, Burkhard and Lisdat, Fred},
  title     = {Differently substituted sulfonated polyanilines - the role of polymer compositions in electron transfer with pyrroloquinoline quinone-dependent glucose dehydrogenase},
  series = {Acta biomaterialia},
  volume    = {9},
  journal   = {Acta biomaterialia},
  number    = {9},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {1742-7061},
  doi       = {10.1016/j.actbio.2013.06.008},
  pages     = {8290 -- 8298},
  year      = {2013},
  abstract  = {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.},
  language  = {en}
}
@article{SarauliXuDietzeletal.2014,
  author    = {Sarauli, David and Xu, Chenggang and Dietzel, Birgit and Schulz, Burkhard and Lisdat, Fred},
  title     = {A multilayered sulfonated polyaniline network with entrapped pyrroloquinoline quinone-dependent glucose dehydrogenase: tunable direct bioelectrocatalysis},
  series = {Journal of materials chemistry : B, Materials for biology and medicine},
  volume    = {2},
  journal   = {Journal of materials chemistry : B, Materials for biology and medicine},
  number    = {21},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2050-750X},
  doi       = {10.1039/c4tb00336e},
  pages     = {3196 -- 3203},
  year      = {2014},
  abstract  = {A feasible approach to construct multilayer films of sulfonated polyanilines - PMSA1 and PABMSA1 containing different ratios of aniline, 2-methoxyaniline-5-sulfonic acid (MAS) and 3-aminobenzoic acid (AB), with the entrapped redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase (PQQ-GDH) on Au and ITO electrode surfaces, is described. The formation of layers has been followed and confirmed by electrochemical impedance spectroscopy (EIS), which demonstrates that the multilayer assembly can be achieved in a progressive and uniform manner. The gold and ITO electrodes subsequently modified with PMSA1:PQQ-GDH and PABMSA1 films are studied by cyclic voltammetry (CV) and UV-Vis spectroscopy which show a significant direct bioelectrocatalytical response to the oxidation of the substrate glucose without any additional mediator. This response correlates linearly with the number of deposited layers. Furthermore, the constructed polymer/enzyme multilayer system exhibits a rather good long-term stability, since the catalytic current response is maintained for more than 60\% of the initial value even after two weeks of storage. This verifies that a productive interaction of the enzyme embedded in the film of substituted polyaniline can be used as a basis for the construction of bioelectronic units, which are useful as indicators for processes liberating glucose and allowing optical and electrochemical transduction.},
  language  = {en}
}
@article{SarauliRiedelWettsteinetal.2012,
  author    = {Sarauli, David and Riedel, Marc and Wettstein, Christoph and Hahn, Robert and Stiba, Konstanze and Wollenberger, Ursula and Leimk{\"u}hler, Silke and Schmuki, Patrik and Lisdat, Fred},
  title     = {Semimetallic TiO2 nanotubes new interfaces for bioelectrochemical enzymatic catalysis},
  series = {Journal of materials chemistry},
  volume    = {22},
  journal   = {Journal of materials chemistry},
  number    = {11},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {0959-9428},
  doi       = {10.1039/c2jm16427b},
  pages     = {4615 -- 4618},
  year      = {2012},
  abstract  = {Different self-organized TiO2 nanotube structures are shown to represent new interfaces for the achievement of bioelectrochemical enzymatic catalysis involving redox proteins and enzymes without further surface modification or the presence of mediators.},
  language  = {en}
}
@article{SarauliPetersXuetal.2014,
  author    = {Sarauli, David and Peters, Kristina and Xu, Chenggang and Schulz, Burkhard and Fattakhova-Rohlfing, Dina and Lisdat, Fred},
  title     = {3D-Electrode architectures for enhanced direct bioelectrocatalysis of pyrroloquinoline quinone-dependent glucose dehydrogenase},
  series = {ACS applied materials \& interfaces},
  volume    = {6},
  journal   = {ACS applied materials \& interfaces},
  number    = {20},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1944-8244},
  doi       = {10.1021/am5046026},
  pages     = {17887 -- 17893},
  year      = {2014},
  abstract  = {We report on the fabrication of a complex electrode architecture for efficient direct bioelectrocatalysis. In the developed procedure, the redox enzyme pyrroloquinoline quinone-dependent glucose dehydrogenase entrapped in a sulfonated polyaniline [poly(2-methoxyaniline-5-sulfonic acid)-co-aniline] was immobilized on macroporous indium tin oxide (macroITO) electrodes. The use of the 3D-conducting scaffold with a large surface area in combination with the conductive polymer enables immobilization of large amounts of enzyme and its efficient communication with the electrode, leading to enhanced direct bioelectrocatalysis. In the presence of glucose, the fabricated bioelectrodes show an exceptionally high direct bioelectrocatalytical response without any additional mediator. The catalytic current is increased more than 200-fold compared to planar ITO electrodes. Together with a high long-term stability (the current response is maintained for >90\% of the initial value even after 2 weeks of storage), the transparent 3D macroITO structure with a conductive polymer represents a valuable basis for the construction of highly efficient bioelectronic units, which are useful as indicators for processes liberating glucose and allowing optical and electrochemical transduction.},
  language  = {en}
}
@article{SarauliBorowskiPetersetal.2016,
  author    = {Sarauli, David and Borowski, Anja and Peters, Kristina and Schulz, Burkhard and Fattakhova-Rohlfing, Dina and Leimk{\"u}hler, Silke and Lisdat, Fred},
  title     = {Investigation of the pH-Dependent Impact of Sulfonated Polyaniline on Bioelectrocatalytic Activity of Xanthine Dehydrogenase},
  series = {ACS catalysis},
  volume    = {6},
  journal   = {ACS catalysis},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {2155-5435},
  doi       = {10.1021/acscatal.6b02011},
  pages     = {7152 -- 7159},
  year      = {2016},
  abstract  = {We report on the pH-dependent bioelectrocatalytic activity of the redox enzyme xanthine dehydrogenase (XDH) in the presence of sulfonated polyaniline PMSA1 (poly(2-methoxyaniline-5-sulfonic acid)-co-aniline). Ultraviolet-visible (UV-vis) spectroscopic measurements with both components in solution reveal electron transfer from the hypoxanthine (HX)-reduced enzyme to the polymer. The enzyme shows bioelectrocatalytic activity on indium tin oxide (ITO) electrodes, when the polymer is present. Depending on solution pH, different processes can be identified. It can be demonstrated that not only product-based communication with the electrode but also efficient polymer-supported bioelectrocatalysis occur. Interestingly, substrate dependent catalytic currents can be obtained in acidic and neutral solutions, although the highest activity of XDH with natural reaction partners is in the alkaline region. Furthermore, operation of the enzyme electrode without addition of the natural cofactor of XDH is feasible. Finally, macroporous ITO electrodes have been used as an immobilization platform for the fabrication of HX-sensitive electrodes. The study shows that the efficient polymer/enzyme interaction can be advantageously combined with the open structure of an electrode material of controlled pore size, resulting in good processability, stability, and defined signal transfer in the presence of a substrate.},
  language  = {en}
}
@article{RiedelSabirSchelleretal.2017,
  author    = {Riedel, M. and Sabir, N. and Scheller, Frieder W. and Parak, Wolfgang J. and Lisdat, Fred},
  title     = {Connecting quantum dots with enzymes},
  series = {Nanoscale},
  volume    = {9},
  journal   = {Nanoscale},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {2040-3364},
  doi       = {10.1039/c7nr00091j},
  pages     = {2814 -- 2823},
  year      = {2017},
  abstract  = {The combination of the biocatalytic features of enzymes with the unique physical properties of nanoparticles in a biohybrid system provides a promising approach for the development of advanced bioelectrocatalytic devices. This study describes the construction of photoelectrochemical signal chains based on CdSe/ZnS quantum dot (QD) modified gold electrodes as light switchable elements, and low molecular weight redox molecules for the combination with different biocatalysts. Photoelectrochemical and photoluminescence experiments verify that electron transfer can be achieved between the redox molecules hexacyanoferrate and ferrocene, and the QDs under illumination. Since for both redox mediators a concentration dependent photocurrent change has been found, light switchable enzymatic signal chains are built up with fructose dehydrogenase (FDH) and pyrroloquinoline quinone-dependent glucose dehydrogenase ((PQQ) GDH) for the detection of sugars. After immobilization of the enzymes at the QD electrode the biocatalytic oxidation of the substrates can be followed by conversion of the redox mediator in solution and subsequent detection at the QD electrode. Furthermore, (PQQ) GDH has been assembled together with ferrocenecarboxylic acid on top of the QD electrode for the construction of a funtional biohybrid architecture, showing that electron transfer can be realized from the enzyme over the redox mediator to the QDs and subsequently to the electrode in a completely immobilized fashion. The results obtained here do not only provide the basis for light-switchable biosensing and bioelectrocatalytic applications, but may also open the way for self-driven point-of-care systems by combination with solar cell approaches (power generation at the QD electrode by enzymatic substrate consumption).},
  language  = {en}
}
@article{LisdatWollenbergerPaeschkeetal.1998,
  author    = {Lisdat, Fred and Wollenberger, Ursula and Paeschke, Manfred and Scheller, Frieder W.},
  title     = {Sensitive catecholamine measurement using a monoenzymatic recycling system},
  year      = {1998},
  language  = {en}
}
@article{LisdatUtepbergenovHaseloffetal.2001,
  author    = {Lisdat, Fred and Utepbergenov, D. and Haseloff, R. F. and Blasig, Ingolf E. and St{\"o}cklein, Walter F. M. and Scheller, Frieder W. and Brigelius-Floh{\´e}, Regina},
  title     = {An optical method for the detection of oxidative stress using protein-RNA interaction},
  year      = {2001},
  language  = {en}
}
@article{LisdatScheller2000,
  author    = {Lisdat, Fred and Scheller, Frieder W.},
  title     = {Technical principles. Electrodes},
  isbn      = {90-5702-447-7},
  year      = {2000},
  language  = {en}
}
@article{LisdatScheller2000,
  author    = {Lisdat, Fred and Scheller, Frieder W.},
  title     = {Principles of sensorial radical detection - a minireview},
  year      = {2000},
  language  = {en}
}
@article{LisdatHoWollenbergeretal.1998,
  author    = {Lisdat, Fred and Ho, Wah O. and Wollenberger, Ursula and Scheller, Frieder W. and Richter, Torsten and Bilitewski, Ursula},
  title     = {Recycling systems based on screen-printed electrodes},
  year      = {1998},
  language  = {en}
}
@article{LisdatGeStoeckleinetal.2000,
  author    = {Lisdat, Fred and Ge, Bixia and St{\"o}cklein, Walter F. M. and Scheller, Frieder W. and Meyer, T.},
  title     = {Electrochemical behaviour and nitric oxides interaction of immobilised cytochrome c from Rhodocyclus gelatinosus},
  year      = {2000},
  language  = {en}
}
@article{LisdatGeScheller1999,
  author    = {Lisdat, Fred and Ge, Bixia and Scheller, Frieder W.},
  title     = {Oligonucleotide-modified electrodes for fast electron transfer to cytochrome c},
  year      = {1999},
  language  = {en}
}
@article{LisdatGeReszkaetal.1999,
  author    = {Lisdat, Fred and Ge, Bixia and Reszka, R. and Kozniewska, E.},
  title     = {An electrochemical method for quantification of the radical scavening activity of SOD},
  year      = {1999},
  language  = {en}
}
@article{LisdatGeMeyerhoffetal.2001,
  author    = {Lisdat, Fred and Ge, Bixia and Meyerhoff, M. E. and Scheller, Frieder W.},
  title     = {Signal chains with cytochromes at SAM modified gold electrodes},
  year      = {2001},
  language  = {en}
}
@article{LisdatGeKrauseetal.2001,
  author    = {Lisdat, Fred and Ge, Bixia and Krause, B. and Ehrlich, A. and Bienert, H. and Scheller, Frieder W.},
  title     = {Nucleic acid-promoted electron transfer to cytochrome c},
  year      = {2001},
  language  = {en}
}
@article{LisdatGeEhrentreichFoersteretal.1999,
  author    = {Lisdat, Fred and Ge, Bixia and Ehrentreich-F{\"o}rster, Eva and Reszka, R. and Scheller, Frieder W.},
  title     = {SOD activity measurement using cytochrome c modified electrode},
  year      = {1999},
  language  = {en}
}
@article{LisdatDronovMoehwaldetal.2009,
  author    = {Lisdat, Fred and Dronov, Roman and M{\"o}hwald, Helmuth and Scheller, Frieder W. and Kurth, Dirk G.},
  title     = {Self-assembly of electro-active protein architectures on electrodes for the construction of biomimetic signal chains},
  issn      = {1359-7345},
  doi       = {10.1039/B813559b},
  year      = {2009},
  abstract  = {The layer-by-layer adsorption technique based on the consecutive deposition of oppositely charged species is for the preparation of protein multilayers with fully electro-active protein molecules. The methodology was established with cytochrome c and the polyelectrolyte sulfonated polyaniline (PASA). The technique is also useful for the construction of bi-protein architectures confining protein-protein communication to an electrode. Following natural examples of protein complexes with defined signal transfer, cytochrome c was arranged with enzymes such as xanthine oxidase, bilirubin oxidase, laccase, and sulfite oxidase in self-assembled multilayer architectures. Thus, biomimetic signal chains from the enzyme substrate via the enzyme and cytochrome c towards the electrode can be established. Communication between proteins immobilised in multiple layers on the electrode can be achieved by in situ generation of small shuttle molecules or more advantageously by direct interprotein electron transfer. This allows the construction of new sensing electrodes, the properties of which can be tuned by the number of deposited protein layers. The mechanism of electron transfer within such protein assemblies on gold electrodes will be discussed.},
  language  = {en}
}
@article{LeiLisdatWollenbergeretal.1999,
  author    = {Lei, Chenghong and Lisdat, Fred and Wollenberger, Ursula and Scheller, Frieder W.},
  title     = {Cytochrome c : Clay-modified electrode},
  year      = {1999},
  language  = {en}
}
@article{KroeningSchellerWollenbergeretal.2004,
  author    = {Kr{\"o}ning, Steffen and Scheller, Frieder W. and Wollenberger, Ursula and Lisdat, Fred},
  title     = {Myoglobin-Clay Electrode for Nitric Oxide (NO) Detection in Solution},
  year      = {2004},
  language  = {en}
}
@article{KrylovAdamzigWalteretal.2006,
  author    = {Krylov, Andrey. V. and Adamzig, H. and Walter, A. D. and Loechel, B. and Kurth, E. and Pulz, O. and Szeponik, Jan and Wegerich, Franziska and Lisdat, Fred},
  title     = {Parallel generation and detection of superoxide and hydrogen peroxide in a fluidic chip},
  series = {Sensors and actuators : B, Chemical},
  volume    = {119},
  journal   = {Sensors and actuators : B, Chemical},
  number    = {1},
  publisher = {Elsevier},
  address   = {Lausanne},
  issn      = {0925-4005},
  doi       = {10.1016/j.snb.2005.11.062},
  pages     = {118 -- 126},
  year      = {2006},
  abstract  = {A fluidic chip system was developed, which combines a stable generation of superoxide radicals and hydrogen peroxide with their sensorial detection. The generation of both reactive oxygen species was achieved by immobilization of xanthine oxidase on controlled pore glass in a reaction chamber. Antioxidants can be introduced into the fluidic chip system by means of mixing chamber. The detection of both species is based on the amperometric principle using a biosensor chip with two working electrodes. As sensing protein for both electrodes cytochrome c was used. The novel system was designed for the quantification of the antioxidant efficiency of different potential scavengers of the respective reactive species in an aqueous medium. Several model antioxidants such as ascorbic acid or catalase have been tested under flow conditions.},
  language  = {en}
}
@article{KrylovPfeilLisdat2004,
  author    = {Krylov, Andrey V. and Pfeil, Wolfgang and Lisdat, Fred},
  title     = {Denaturation and renaturation of cytochrome c immobilized on gold electrodes in DMSO-containing buffers},
  year      = {2004},
  abstract  = {Cytochrome c (cyt c) was immobilized on surface-modified gold electrodes using a self-assembling approach. The resulting cyt c electrode was studied using cyclic voltammetry. Compared to pure phosphate buffer, cyt c electrodes exhibited in DMSO-containing solutions lower oxidation and reduction peak currents, which originated from a decrease in the addressable electro-active amount of the surface-immobilized protein. This is associated with the process of protein denaturation. The denaturation kinetics can be described by a sum of two processes with time constants differing by more than one order of magnitude. The subsequent change of the aqueous/organic medium back to a pure aqueous buffer resulted in a shift of the formal potential to its initial value and a partial recovery of the peak current. This can be attributed to the renaturation of the cyt c. The extent of renaturation depended on the organic solvent/water ratio of the mixture used. The kinetics of protein renaturation were similar to those of the denaturation process. (C) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{KrylovBeissenhirtzAdamzigetal.2004,
  author    = {Krylov, Andrey V. and Beissenhirtz, Moritz Karl and Adamzig, Holger and Scheller, Frieder W. and Lisdat, Fred},
  title     = {Thick-film electrodes for measurement of superoxide and hydrogen peroxide based on direct protein-electrode contacts},
  year      = {2004},
  abstract  = {Cytochrome c was immobilized on screen-printed thick-film gold electrodes by a self-assembly approach using mixed monolayers of mercaptoundecanoic acid and mercaptoundecanol. Cyclic voltammetry revealed quasi-reversible electrochemical behavior of the covalently fixed protein with a formal potential of +10 mV vs. Ag/AgCl. Polarized at +150 mV vs. Ag/AgCl the electrode was found to be sensitive to superoxide radicals in the range 300-1200 nmol L-1. Compared with metal needle electrodes sensitivity and reproducibility could be improved and combined with the easiness of preparation. This allows the fabrication of disposable sensors for nanomolar superoxide concentrations. By changing the electrode potential the sensor can be switched from response to superoxide radicals to hydrogen peroxide-another reactive oxygen species. H2O2 sensitivity can be provided in the range 10-1000 mumol L-1 which makes the electrode suitable for oxidative stress studies},
  language  = {en}
}
@article{KepplingerLisdatWollenberger2011,
  author    = {Kepplinger, Christian and Lisdat, Fred and Wollenberger, Ursula},
  title     = {Cytochrome c/polyelectrolyte multilayers investigated by E-QCM-D - effect of temperature on the assembly structure},
  series = {Langmuir},
  volume    = {27},
  journal   = {Langmuir},
  number    = {13},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {0743-7463},
  doi       = {10.1021/la200860p},
  pages     = {8309 -- 8315},
  year      = {2011},
  abstract  = {Protein multilayers, consisting of cytochrome c (cyt c) and poly(aniline sulfonic acid) (PASA), are investigated by electrochemical quartz crystal microbalance with dissipation monitoring (E-QCM-D). This technique reveals that a four-bilayer assembly has rather rigid properties. A thickness of 16.3 +/- 0.8 nm is calculated with the Sauerbrey equation and is found to be in good agreement with a viscoelastic model. The electroactive amount of cyt c is estimated by the deposited mass under the assumption of 50\% coupled water. Temperature-induced stabilization of the multilayer assembly has been investigated in the temperature range between 30 and 45 degrees C. The treatment results in a loss of material and a contraction of the film. The electroactive amount of cyt c also decreases during heating and remains constant after the cooling period. The contraction of the film is accompanied by the enhanced stability of the assembly. In addition, it is found that cyt c and PASA can be assembled at higher temperatures, resulting in the formation of multilayer systems with less dissipation.},
  language  = {en}
}
@article{KappBeissenhirtzGeyeretal.2006,
  author    = {Kapp, Andreas and Beissenhirtz, Moritz Karl and Geyer, F. and Scheller, Frieder W. and Viezzoli, Maria Silvia and Lisdat, Fred},
  title     = {Electrochemical and sensorial behaviour of SOD mutants immobilized on gold electrodes in aqueous / organic solvent mixtures},
  issn      = {1040-0397},
  doi       = {10.1002/elan.200603620},
  year      = {2006},
  language  = {en}
}
@article{KappBeissenhirtzGeyeretal.2006,
  author    = {Kapp, A. and Beissenhirtz, Moritz Karl and Geyer, F. and Scheller, F. and Viezzoli, Maria Silvia and Lisdat, Fred},
  title     = {Electrochemical and sensorial behavior of SOD mutants immobilized on gold electrodes in aqueous/organic solvent mixtures},
  series = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis},
  volume    = {18},
  journal   = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1040-0397},
  doi       = {10.1002/elan.200603620},
  pages     = {1909 -- 1915},
  year      = {2006},
  abstract  = {A cysteine mutant of a monomeric human Cu, Zn-SOD (Glycine 61, Serine 142) has been immobilized directly on gold electrodes using the thiol groups introduced. The electrochemical behavior of the surface confined protein was studied in mixtures of aqueous buffer and DMSO up to an organic solvent content of 60\%. The formal potential was found to be rather independent of the DMSO content. However, half peak width increased and the redoxactive amount clearly decreased with raising DMSO content. In addition, the kinetics of the heterogeneous electron transfer became slower; but still a quasireversible electrochemical conversion of the mutant SOD was feasible. Thus, the electrodes were applied for sensorial superoxide detection. At a potential of +220 mV vs. Ag/AgCl advantage was taken of the partial oxidation reaction of the enzyme. A defined superoxide signal was obtained in solutions up to 40\% DMSO. The sensitivity of the mutant electrodes decreased linearly with the organic solvent content in solution but was still higher compared to conventional cyt.c based sensors. At DMSO concentrations higher than 40\% no sensor response was detected.},
  language  = {en}
}
@article{KammerKellingBaieretal.2009,
  author    = {Kammer, Stefan and Kelling, Alexandra and Baier, Heiko and Mickler, Wulfhard and Dosche, Carsten and Rurack, Knut and Kapp, Andreas and Lisdat, Fred and Holdt, Hans-J{\"u}rgen},
  title     = {2,11-dialkylated 1,12-diazaperylene copper(I) complexes : first supramolecular column assemblies by pi-pi stacking between homoleptic tetrahedral metal complexes, exhibiting low-energy MLCT transitions},
  issn      = {1434-1948},
  doi       = {10.1002/ejic.200900695},
  year      = {2009},
  abstract  = {2,11-Dialkylated 1,12-diazaperylenes (alkyl = Me, Et, iPr) dmedap, detdap and dipdap have been synthesized by reductive cyclization of 3,3-dialkylated 1,1-biisoquinolines 3a-c, resulting in the first copper(I) complexes of a large- surface ligand. The new copper(I) complexes show low-energy MLCT absorptions unprecedented for bis(-diimin)copper(I) complexes. The solid structures of the complexes[Cu(dipdap)2]BF4·CH2Cl2·1.5H2O, [Cu(dipdap)2]OTf·CH2Cl2, [Cu(dipdap)2]I·C2H4Cl2·THF·2H2O, [Cu(dmedap)2]OTf and [Cu(dipdap)2]AQSO3·H2O (AQSO3 = sodium 9,10-dihydro-9,10-dioxo-2- anthracenesulfonate) are reported. In [Cu(dipdap)2]BF4·CH2Cl2·1.5H2O, each copper(I) complex cation interacts with two others by - stacking interactions forming a novel supramolecular column structural motif running along the crystallographic c axis. In the crystalline compound [Cu(dipdap)2]AQSO3·H2O, aggregation between two complex cations and two additional anions by - stacking interactions is observed, leading to a tetrameric assembly. Furthermore, the three complex compounds [Cu(L)2]BF4 (L = dmedap, detdap, dipdap) were tested for sensory applications in aqueous buffer solutions in electrochemical studies of the complex immobilized on glassy carbon electrodes.},
  language  = {en}
}
@article{JuLiuGeetal.2000,
  author    = {Ju, Huangxian and Liu, Songqin and Ge, Bixia and Lisdat, Fred and Scheller, Frieder W.},
  title     = {Electrochemistry of cytochrome c immobilized on colloidal gold modified carbon paste electrodes and its electrocatalytic activity},
  year      = {2000},
  language  = {en}
}
@article{IgnatovShishniashviliGeetal.2002,
  author    = {Ignatov, S. and Shishniashvili, D. and Ge, Bixia and Scheller, Frieder W. and Lisdat, Fred},
  title     = {Amperometric biosensor based on a functionalized gold electrode for the detection of antioxidants},
  year      = {2002},
  language  = {en}
}
@article{IgnatovGeSchelleretal.2001,
  author    = {Ignatov, S. and Ge, Bixia and Scheller, Frieder W. and Lisdat, Fred},
  title     = {Detection of the antioxidant activity detection of flavonoids by using superoxide sensor},
  isbn      = {1-58603-164-3},
  year      = {2001},
  language  = {en}
}
@article{HeinsohnNiedlAnielskietal.2022,
  author    = {Heinsohn, Natascha Katharina and Niedl, Robert Raimund and Anielski, Alexander and Lisdat, Fred and Beta, Carsten},
  title     = {Electrophoretic mu PAD for purification and analysis of DNA samples},
  series = {Biosensors : open access journal},
  volume    = {12},
  journal   = {Biosensors : open access journal},
  number    = {2},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-6374},
  doi       = {10.3390/bios12020062},
  pages     = {15},
  year      = {2022},
  abstract  = {In this work, the fabrication and characterization of a simple, inexpensive, and effective microfluidic paper analytic device (mu PAD) for monitoring DNA samples is reported. The glass microfiber-based chip has been fabricated by a new wax-based transfer-printing technique and an electrode printing process. It is capable of moving DNA effectively in a time-dependent fashion. The nucleic acid sample is not damaged by this process and is accumulated in front of the anode, but not directly on the electrode. Thus, further DNA processing is feasible. The system allows the DNA to be purified by separating it from other components in sample mixtures such as proteins. Furthermore, it is demonstrated that DNA can be moved through several layers of the glass fiber material. This proof of concept will provide the basis for the development of rapid test systems, e.g., for the detection of pathogens in water samples.},
  language  = {en}
}
@article{GeSchellerLisdat2003,
  author    = {Ge, Bixia and Scheller, Frieder W. and Lisdat, Fred},
  title     = {Electrochemistry of immobilized CuZnSOD and FeSOD and their interaction with superoxide radicals},
  year      = {2003},
  abstract  = {Copper, zinc superoxide dismutase (CuZnSOD) from bovine erythrocytes and iron superoxide dismutase from Escherichia coli (FeSOD) were immobilized on 3-mercaptopropionic acid (MPA)-modified gold electrodes, respectively. The characterization of the SOD electrodes showed a quasi-reversible, electrochemical redox behavior with a formal potential of 47 {\~n} 4 mV and -154 {\~n} 5 mV (vs. Ag/AgCl, 1 M KCl) for surface adsorbed CuZnSOD and FeSOD, respectively. The heterogeneous electron transfer rate constants were determined to be about 65 and 35/s, respectively. Covalent fixation of both SODs was also feasible with only slight changes in the formal potential. The interaction of superoxide radicals (O2-) with the SOD electrode was investigated. No catalytic current could be observed. However, due to the fast cyclic reaction of SOD with superoxide, the communication of the protein with the electrode was strongly influenced. The amperometric detection of superoxide radicals is discussed.},
  language  = {en}
}
@article{GeMeyerSchoeningetal.2000,
  author    = {Ge, Bixia and Meyer, T. and Sch{\"o}ning, M. J. and Wollenberger, Ursula and Lisdat, Fred},
  title     = {Cytochrome c from chromatium vinosum on gold electrodes},
  year      = {2000},
  language  = {en}
}
@article{GeLisdat2002,
  author    = {Ge, Bixia and Lisdat, Fred},
  title     = {Superoxide sensor based on cytochrome c immobilized on mixed-thiol SAM with a new calibration method},
  year      = {2002},
  language  = {en}
}
@article{FridmanWollenbergerBogdanovskayaetal.2000,
  author    = {Fridman, Vadim and Wollenberger, Ursula and Bogdanovskaya, V. A. and Lisdat, Fred and Ruzgas, T. and Lindgren, A. and Gorton, Lo and Scheller, Frieder W.},
  title     = {Electrochemical investigation of cellobiose oxidation by cellobiose dehydrogenase in the presence of cytochrome c as mediator},
  year      = {2000},
  language  = {en}
}
@article{FandrichBullerWischerhoffetal.2012,
  author    = {Fandrich, Artur and Buller, Jens and Wischerhoff, Erik and Laschewsky, Andr{\´e} and Lisdat, Fred},
  title     = {Electrochemical detection of the thermally induced phase transition of a thin stimuli-responsive polymer film},
  series = {ChemPhysChem : a European journal of chemical physics and physical chemistry},
  volume    = {13},
  journal   = {ChemPhysChem : a European journal of chemical physics and physical chemistry},
  number    = {8},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1439-4235},
  doi       = {10.1002/cphc.201100924},
  pages     = {2020 -- 2023},
  year      = {2012},
  language  = {en}
}
@article{FandrichBullerSchaeferetal.2015,
  author    = {Fandrich, Artur and Buller, Jens and Sch{\"a}fer, Daniel and Wischerhoff, Erik and Laschewsky, Andr{\´e} and Lisdat, Fred},
  title     = {Electrochemical characterization of a responsive macromolecular interface on gold},
  series = {Physica status solidi : A, Applications and materials science},
  volume    = {212},
  journal   = {Physica status solidi : A, Applications and materials science},
  number    = {6},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1862-6300},
  doi       = {10.1002/pssa.201431698},
  pages     = {1359 -- 1367},
  year      = {2015},
  abstract  = {This study reports on the investigation of a thermoresponsive polymer as a thin film on electrodes and the influence of coupling a peptide and an antibody to the film. The utilized polymer from the class of poly(oligoethylene glycol)-methacrylate polymers (poly(OEGMA)) with carboxy functions containing side chains was synthesized and properly characterized in aqueous solutions. The dependence of the cloud point on the pH of the surrounding media is discussed. The responsive polymer was immobilized on gold electrodes as shown by electrochemical, quartz crystal microbalance (QCM), and atomic force microscopy (AFM) techniques. The temperature dependent behavior of the polymer covalently grafted to gold substrates is investigated using cyclic voltammetry (CV) in ferro-/ferricyanide solution. Significant changes in the slope of the temperature-dependence of the voltammetric peak current and the peak separation values clearly indicate the thermally induced conformational change on the surface. Finally, a biorecognition reaction between a short FLAG peptide (N-Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys-C) covalently immobilized on the polymer interface and the corresponding IgG antibody was performed. The study shows that the responsiveness of the electrode is retained after peptide coupling and antibody binding, although the response is diminished.},
  language  = {en}
}
@article{FandrichBullerMemczaketal.2017,
  author    = {Fandrich, Artur and Buller, Jens and Memczak, Henry and Stoecklein, W. and Hinrichs, K. and Wischerhoff, E. and Schulz, B. and Laschewsky, Andr{\´e} and Lisdat, Fred},
  title     = {Responsive Polymer-Electrode Interface-Study of its Thermo- and pH-Sensitivity and the Influence of Peptide Coupling},
  series = {Electrochimica acta : the journal of the International Society of Electrochemistry (ISE)},
  volume    = {229},
  journal   = {Electrochimica acta : the journal of the International Society of Electrochemistry (ISE)},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0013-4686},
  doi       = {10.1016/j.electacta.2017.01.080},
  pages     = {325 -- 333},
  year      = {2017},
  abstract  = {This study introduces a thermally responsive, polymer-based electrode system. The key component is a surface-attached, temperature-responsive poly(oligoethylene glycol) methacrylate (poly(OEGMA)) type polymer bearing photoreactive benzophenone and carboxy groups containing side chains. The responsive behavior of the polymer in aqueous media has been investigated by turbidimetry measurements. Polymer films are formed on gold substrates by means of the photoreactive 2(dicyclohexylphosphino)benzophenone (DPBP) through photocrosslinking. The electrochemical behavior of the resulting polymer-substrate interface has been investigated in buffered [Fe(CN)6](3-)/[Fe (CN)6](4-)solutions at room temperature and under temperature variation by cyclic voltammetry (CV). The CV experiments show that with increasing temperature structural changes of the polymer layer occur, which alter the output of the electrochemical measurement. Repeated heating/cooling cycles analyzed by CV measurements and pH changes analyzed by quartz crystal microbalance with dissipation monitoring (QCM-D) reveal the reversible nature of the restructuring process. The immobilized films are further modified by covalent coupling of two small biomolecules - a hydrophobic peptide and a more hydrophilic one. These attached components influence the hydrophobicity of the layer in a different way the resulting change of the temperature-caused behavior has been studied by CV indicating a different state of the polymer after coupling of the hydrophobic peptide.},
  language  = {en}
}
@article{ChenWollenbergerLisdatetal.2000,
  author    = {Chen, Jian and Wollenberger, Ursula and Lisdat, Fred and Ge, Bixia and Scheller, Frieder W.},
  title     = {Superoxide sensor based on hemin modified electrode},
  year      = {2000},
  language  = {en}
}