@article{BadalyanDierichStibaetal.2014,
  author    = {Badalyan, Artavazd and Dierich, Marlen and Stiba, Konstanze and Schwuchow, Viola and Leimk{\"u}hler, Silke and Wollenberger, Ulla},
  title     = {Electrical wiring of the aldehyde oxidoreductase PaoABC with a polymer containing osmium redox centers},
  series = {Biosensors},
  volume    = {4},
  journal   = {Biosensors},
  number    = {4},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/bios4040403},
  pages     = {403 -- 421},
  year      = {2014},
  abstract  = {Biosensors for the detection of benzaldehyde and g-aminobutyric acid (GABA) are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below -0.15 V (vs. Ag|AgCl, 1 M KCl). The pH-dependence of benzaldehyde oxidation can be strongly influenced by the ionic strength. The effect is similar with the soluble osmium redox complex and therefore indicates a clear electrostatic effect on the bioelectrocatalytic efficiency of PaoABC in the osmium containing redox polymer. At lower ionic strength, the pH-optimum is high and can be switched to low pH-values at high ionic strength. This offers biosensing at high and low pH-values. A "reagentless" biosensor has been formed with enzyme wired onto a screen-printed electrode in a flow cell device. The response time to addition of benzaldehyde is 30 s, and the measuring range is between 10-150 µM and the detection limit of 5 µM (signal to noise ratio 3:1) of benzaldehyde. The relative standard deviation in a series (n = 13) for 200 µM benzaldehyde is 1.9\%. For the biosensor, a response to succinic semialdehyde was also identified. Based on this response and the ability to work at high pH a biosensor for GABA is proposed by coimmobilizing GABA-aminotransferase (GABA-T) and PaoABC in the osmium containing redox polymer.},
  language  = {en}
}
@misc{BadalyanDierichStibaetal.2014,
  author    = {Badalyan, Artavazd and Dierich, Marlen and Stiba, Konstanze and Schwuchow, Viola and Leimk{\"u}hler, Silke and Wollenberger, Ulla},
  title     = {Electrical wiring of the aldehyde oxidoreductase PaoABC with a polymer containing osmium redox centers},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1082},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-47507},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-475070},
  pages     = {21},
  year      = {2014},
  abstract  = {Biosensors for the detection of benzaldehyde and g-aminobutyric acid (GABA) are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below -0.15 V (vs. Ag|AgCl, 1 M KCl). The pH-dependence of benzaldehyde oxidation can be strongly influenced by the ionic strength. The effect is similar with the soluble osmium redox complex and therefore indicates a clear electrostatic effect on the bioelectrocatalytic efficiency of PaoABC in the osmium containing redox polymer. At lower ionic strength, the pH-optimum is high and can be switched to low pH-values at high ionic strength. This offers biosensing at high and low pH-values. A "reagentless" biosensor has been formed with enzyme wired onto a screen-printed electrode in a flow cell device. The response time to addition of benzaldehyde is 30 s, and the measuring range is between 10-150 µM and the detection limit of 5 µM (signal to noise ratio 3:1) of benzaldehyde. The relative standard deviation in a series (n = 13) for 200 µM benzaldehyde is 1.9\%. For the biosensor, a response to succinic semialdehyde was also identified. Based on this response and the ability to work at high pH a biosensor for GABA is proposed by coimmobilizing GABA-aminotransferase (GABA-T) and PaoABC in the osmium containing redox polymer.},
  language  = {en}
}
@phdthesis{Badalyan2013,
  author    = {Badalyan, Artavazd},
  title     = {Bioelectrochemistry of molybdenum hydroxylases : aldehyde oxidoreductase PaoABC from escherichia coli and xanthine dehydrogenase from rhodobacter capsulatus},
  address   = {Potsdam},
  pages     = {117 S.},
  year      = {2013},
  language  = {en}
}
@article{BadalyanYogaSchwuchowetal.2013,
  author    = {Badalyan, Artavazd and Yoga, Etienne Galemou and Schwuchow, Viola and P{\"o}ller, Sascha and Schuhmann, Wolfgang and Leimk{\"u}hler, Silke and Wollenberger, Ursula},
  title     = {Analysis of the interaction of the molybdenum hydroxylase PaoABC from Escherichia coli with positively and negatively charged metal complexes},
  series = {Electrochemistry communications : an international journal dedicated to rapid publications in electrochemistry},
  volume    = {37},
  journal   = {Electrochemistry communications : an international journal dedicated to rapid publications in electrochemistry},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {1388-2481},
  doi       = {10.1016/j.elecom.2013.09.017},
  pages     = {5 -- 7},
  year      = {2013},
  abstract  = {An unusual behavior of the periplasmic aldehyde oxidoreductase (PaoABC) from Escherichia coil has been observed from electrochemical investigations of the enzyme catalyzed oxidation of aromatic aldehydes with different mediators under different conditions of ionic strength. The enzyme has similarity to other molybdoenzymes of the xanthine oxidase family, but the catalytic behavior turned out to be very different. Under steady state conditions the turnover of PaoABC is maximal at pH 4 for the negatively charged ferricyanide and at pH 9 for a positively charged osmium complex. Stopped-flow kinetic measurements of the catalytic half reaction showed that oxidation of benzaldehyde proceeds also above pH 7. Thus, benzaldehyde oxidation can proceed under acidic and basic conditions using this enzyme, a property which has not been described before for molybdenum hydroxylases. It is also suggested that the electron transfer with artificial electron acceptors and PaoABC can proceed at different protein sites and depends on the nature of the electron acceptor in addition to the ionic strength. (C) 2013 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{YarmanBadalyanGajovicEichelmannetal.2011,
  author    = {Yarman, Aysu and Badalyan, Artavazd and Gajovic-Eichelmann, Nenad and Wollenberger, Ursula and Scheller, Frieder W.},
  title     = {Enzyme electrode for aromatic compounds exploiting the catalytic activities of microperoxidase-11},
  series = {Biosensors and bioelectronics : the principal international journal devoted to research, design development and application of biosensors and bioelectronics},
  volume    = {30},
  journal   = {Biosensors and bioelectronics : the principal international journal devoted to research, design development and application of biosensors and bioelectronics},
  number    = {1},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0956-5663},
  doi       = {10.1016/j.bios.2011.09.004},
  pages     = {320 -- 323},
  year      = {2011},
  abstract  = {Microperoxidase-11 (MR-11) which has been immobilised in a matrix of chitosan-embedded gold nanoparticles on the surface of a glassy carbon electrode catalyzes the conversion of aromatic substances. This peroxide-dependent catalysis of microperoxidase has been applied in an enzyme electrode for the first time to indicate aromatic compounds such as aniline. 4-fluoroaniline, catechol and p-aminophenol. The electrode signal is generated by the cathodic reduction of the quinone or quinoneimine which is formed in the presence of both MP-II and peroxide from the substrate. The same sensor principle will be extended to aromatic drugs.},
  language  = {en}
}
@article{DeyAdamovskiFriebeetal.2014,
  author    = {Dey, Pradip and Adamovski, Miriam and Friebe, Simon and Badalyan, Artavazd and Mutihac, Radu-Cristian and Paulus, Florian and Leimk{\"u}hler, Silke and Wollenberger, Ursula and Haag, Rainer},
  title     = {Dendritic polyglycerol-poly(ethylene glycol)-based polymer networks for biosensing application},
  series = {ACS applied materials \& interfaces},
  volume    = {6},
  journal   = {ACS applied materials \& interfaces},
  number    = {12},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1944-8244},
  doi       = {10.1021/am502018x},
  pages     = {8937 -- 8941},
  year      = {2014},
  abstract  = {This work describes the formation of a new dendritic polyglycerol-poly(ethylene glycol)-based 3D polymer network as a matrix for immobilization of the redox enzyme periplasmatic aldehyde oxidoreductase to create an electrochemical biosensor. The novel network is built directly on the gold surface, where it simultaneously stabilizes the enzyme for up to 4 days. The prepared biosensors can be used for amperometric detection of benzaldehyde in the range of 0.8-400 mu M.},
  language  = {en}
}
@article{BadalyanNeumannSchaalLeimkuehleretal.2013,
  author    = {Badalyan, Artavazd and Neumann-Schaal, Meina and Leimk{\"u}hler, Silke and Wollenberger, Ursula},
  title     = {A Biosensor for aromatic aldehydes comprising the mediator dependent PaoABC-Aldehyde oxidoreductase},
  series = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis},
  volume    = {25},
  journal   = {Electroanalysis : an international journal devoted to fundamental and practical aspects of electroanalysis},
  number    = {1},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1040-0397},
  doi       = {10.1002/elan.201200362},
  pages     = {101 -- 108},
  year      = {2013},
  abstract  = {A novel aldehyde oxidoreductase (PaoABC) from Escherichia coli was utilized for the development of an oxygen insensitive biosensor for benzaldehyde. The enzyme was immobilized in polyvinyl alcohol and currents were measured for aldehyde oxidation with different one and two electron mediators with the highest sensitivity for benzaldehyde in the presence of hexacyanoferrate(III). The benzaldehyde biosensor was optimized with respect to mediator concentration, enzyme loading and pH using potassium hexacyanoferrate(III). The linear measuring range is between 0.5200 mu M benzaldehyde. In correspondence with the substrate selectivity of the enzyme in solution the biosensor revealed a preference for aromatic aldehydes and less effective conversion of aliphatic aldehydes. The biosensor is oxygen independent, which is a particularly attractive feature for application. The biosensor can be applied to detect contaminations with benzaldehyde in solvents such as benzyl alcohol, where traces of benzaldehyde in benzyl alcohol down to 0.0042?\% can be detected.},
  language  = {en}
}