@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{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}
}