@article{SchoeningPoghossianSchultze2003,
  author    = {Sch{\"o}ning, Michael Josef and Poghossian, Arshak and Schultze, Joachim W.},
  title     = {Measuring seven parameters by two ISFET modules in a microcell set-up},
  series = {Int. Journal of Computational Engineering Science. 4 (2003), H. 2},
  journal   = {Int. Journal of Computational Engineering Science. 4 (2003), H. 2},
  isbn      = {1465-8763},
  pages     = {257 -- 260},
  year      = {2003},
  language  = {en}
}
@article{HuckPoghossianBaeckeretal.2015,
  author    = {Huck, Christina and Poghossian, Arshak and B{\"a}cker, Matthias and Reisert, Steffen and Kramer, Friederike and Begoyan, Vardges K. and Buniatyan, Vahe V. and Sch{\"o}ning, Michael Josef},
  title     = {Multi-parameter sensing using high-k oxide of barium strontium titanate},
  series = {Physica status solidi (a)},
  volume    = {212},
  journal   = {Physica status solidi (a)},
  number    = {6},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1862-6319},
  doi       = {10.1002/pssa.201431911},
  pages     = {1259},
  year      = {2015},
  abstract  = {High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors. In this work, a Si-based sensor chip containing Pt interdigitated electrodes covered with a thin BST layer (485 nm) has been developed for multi-parameter chemical sensing. The chip has been applied for the contactless measurement of the electrolyte conductivity, the detection of adsorbed charged macromolecules (positively charged polyelectrolytes of polyethylenimine) and the concentration of hydrogen peroxide (H2O2) vapor. The experimental results of functional testing of individual sensors are presented. The mechanism of the BST sensitivity to charged polyelectrolytes and H2O2 vapor has been proposed and discussed.},
  language  = {en}
}
@article{AboulnagaZouSelmeretal.2018,
  author    = {Aboulnaga, Elhussiny A. and Zou, Huibin and Selmer, Thorsten and Xian, Mo},
  title     = {Development of a plasmid-based, tunable, tolC-derived expression system for application in Cupriavidus necator H16},
  series = {Journal of Biotechnology},
  volume    = {274},
  journal   = {Journal of Biotechnology},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0168-1656},
  doi       = {10.1016/j.jbiotec.2018.03.007},
  pages     = {15 -- 27},
  year      = {2018},
  abstract  = {Cupriavidus necator H16 gains increasing attention in microbial research and biotechnological application due to its diverse metabolic features. Here we present a tightly controlled gene expression system for C. necator including the pBBR1-vector that contains hybrid promoters originating from C. necator native tolC-promoter in combination with a synthetic tetO-operator. The expression of the reporter gene from these plasmids relies on the addition of the exogenous inducer doxycycline (dc). The novel expression system offers a combination of advantageous features as; (i) high and dose-dependent recombinant protein production, (ii) tight control with a high dynamic range (On/Off ratio), which makes it applicable for harmful pathways or for toxic protein production, (iii) comparable cheap inducer (doxycycline, dc), (iv) effective at low inducer concentration, that makes it useful for large scale application, (v) rapid, diffusion controlled induction, and (vi) the inducer does not interfere within the cell metabolism. As applications of the expression system in C. necator H16, the growth ability on glycerol was enhanced by constitutively expressing the E. coli glpk gene-encoding for glycerol kinase. Likewise, we used the system to overcome the expression toxicity of mevalonate pathway in C. necator H16. With this system, the mevalonate-genes were successfully introduced in the host and the recombinant strains could produce about 200 mg/l mevalonate.},
  language  = {en}
}
@article{IkenAhlbornGerlachetal.2013,
  author    = {Iken, Heiko and Ahlborn, Kristina and Gerlach, Frank and Vonau, Winfried and Zander, Wilhelm and Schubert, J{\"u}rgen P. and Sch{\"o}ning, Michael Josef},
  title     = {Development of redox glasses and subsequent processing by means of pulsed laser deposition for realizing silicon-based thin-film sensors},
  series = {Electrochimica acta},
  journal   = {Electrochimica acta},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1873-3859 (E-Journal); 0013-4686 (Print)},
  pages     = {Available online 30.8.2013},
  year      = {2013},
  language  = {en}
}
@article{GrinsvenVandenBonGrietenetal.2011,
  author    = {Grinsven, Bart van and Vanden Bon, Natalie and Grieten, Lars and Murib, Mohammed Sharif and Janssen, Stoffel Dominique and Haenen, Ken and Schneider, E. and Ingebrandt, Sven and Sch{\"o}ning, Michael Josef and Vermeeren, Veronique and Ameloot, Marcel and Michiels, Luc and Thoelen, Ronald and De Ceuninck, Ward A. and Wagner, Patrick},
  title     = {Rapid assessment of the stability of DNA duplexes by impedimetric real-time monitoring of chemically induced denaturation},
  series = {Lab on a Chip},
  volume    = {11},
  journal   = {Lab on a Chip},
  number    = {9},
  publisher = {Royal Society of Chemistry (RSC)},
  address   = {Cambridge},
  isbn      = {1473-0197},
  pages     = {1656 -- 1663},
  year      = {2011},
  language  = {en}
}
@article{MuribGrinsvenGrietenetal.2013,
  author    = {Murib, M. S. and Grinsven, B. van and Grieten, L. and Janssens, S. D. and Vermeeren, V. and Eersels, K. and Broeders, J. and Ameloot, Marcel and Michiels, L. and Ceuninck, W. De and Haenen, K. and Sch{\"o}ning, Michael Josef and Wagner, Patrick},
  title     = {Electronic monitoring of chemical DNA denaturation on nanocrystalline diamond electrodes with different molarities and flow rates},
  series = {Physica Status Solidi (A). Vol. 210 (2013), iss. 5},
  journal   = {Physica Status Solidi (A). Vol. 210 (2013), iss. 5},
  publisher = {Wiley-VCH},
  address   = {Berlin},
  issn      = {0031-8965},
  pages     = {911 -- 917},
  year      = {2013},
  language  = {en}
}
@article{MuribYeapEurlingsetal.2016,
  author    = {Murib, M. S. and Yeap, W. S. and Eurlings, Y. and Grinsven, B. van and Boyen, H.-G. and Conings, B. and Michiels, L. and Ameloot, Marcel and Carleer, R. and Warmer, J. and Kaul, P. and Haenen, K. and Sch{\"o}ning, Michael Josef and Ceuninck, W. de and Wagner, P.},
  title     = {Heat-transfer based characterization of DNA on synthetic sapphire chips},
  series = {Sensors and Actuators B: Chemical},
  volume    = {230},
  journal   = {Sensors and Actuators B: Chemical},
  number    = {230},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0925-4005},
  doi       = {10.1016/j.snb.2016.02.027},
  pages     = {260 -- 271},
  year      = {2016},
  abstract  = {In this study, we show that synthetic sapphire (Al₂O₃), an established implant material, can also serve as a platform material for biosensors comparable to nanocrystalline diamond. Sapphire chips, beads, and powder were first modified with (3-aminopropyl) triethoxysilane (APTES), followed by succinic anhydride (SA), and finally single-stranded probe DNA was EDC coupled to the functionalized layer. The presence of the APTES-SA layer on sapphire powders was confirmed by thermogravimetric analyis and Fourier-transform infrared spectroscopy. Using planar sapphire chips as substrates and X-ray photoelectron spectroscopy (XPS) as surface-sensitive tool, the sequence of individual layers was analyzed with respect to their chemical state, enabling the quantification of areal densities of the involved molecular units. Fluorescence microscopy was used to demonstrate the hybridization of fluorescently tagged target DNA to the probe DNA, including denaturation- and re-hybridization experiments. Due to its high thermal conductivity, synthetic sapphire is especially suitable as a chip material for the heat-transfer method, which was employed to distinguish complementary- and non-complementary DNA duplexes containing single-nucleotide polymorphisms. These results indicate that it is possible to detect mutations electronically with a chemically resilient and electrically insulating chip material.},
  language  = {en}
}
@inproceedings{KirchnerSpelthahnSchoeningetal.2010,
  author    = {Kirchner, Patrick and Spelthahn, Heiko and Sch{\"o}ning, Michael Josef and Henkel, Hartmut and Schneider, Andreas and Friedrich, Peter and Kolstad, Jens and Berger, J{\"o}rg},
  title     = {Realisierung eines Polyimid-basierten kalorimetrischen Gassensors zur Inline-{\"U}berwachung der H2O2-Konzentration in aseptischen Abf{\"u}llsystemen},
  series = {Tagungsband: Sensoren und Messsysteme 2010},
  booktitle = {Tagungsband: Sensoren und Messsysteme 2010},
  publisher = {VDE Verlag},
  address   = {Berlin},
  isbn      = {978-3-8007-3260-9},
  pages     = {607 -- 612},
  year      = {2010},
  abstract  = {In aseptischen Abf{\"u}llsystemen wird Wasserstoffperoxid in der Gasphase aufgrund der stark oxidativen Wirkung zur Packstoffentkeimung eingesetzt. Dabei wird die Effizienz der Entkeimung im Wesentlichen von der vorliegenden H2O2-Konzentration im Packstoff bestimmt. Zur Inline-{\"U}berwachung der H2O2-Konzentration wurde ein kalorimetrischer Gassensor auf Basis einer flexiblen Polyimidfolie aus temperatursensitiven D{\"u}nnschicht-Widerst{\"a}nden und Mangan(IV)-oxid als katalytische Transducerschicht realisiert. Der Sensor weist ein lineares Ansprechverhalten mit einer Sensitivit{\"a}t von 7,15 °C/Vol.-\% in einem H2O2-Konzentrationsbereich von 0 bis 8 Vol.-\% auf. Weiterhin wurde zur Auslesung des Sensorsignals eine RFID-Elektronik, bestehend aus einem Sensor-Tag und einer Sende-/Empfangseinheit ausgelegt, sowie eine Abfolge des Messzyklus aufgestellt. Im weiteren Verlauf soll der kalorimetrische Gassensor mit der RFID-Elektronik gekoppelt und in eine Testverpackung zur Inline-{\"U}berwachung der H2O2-Konzentration in aseptischen Abf{\"u}llsystemen implementiert werden.},
  language  = {de}
}
@inproceedings{WernerSpelthahnSchoeningetal.2010,
  author    = {Werner, Frederik and Spelthahn, Heiko and Sch{\"o}ning, Michael Josef and Krumbe, Christoph and Wagner, Torsten and Yoshinobu, Tatsuo and Keusgen, Michael},
  title     = {Neue Ansteuerungselektronik f{\"u}r LAPS-basierte Biosensoren zur gleichzeitig ortsaufgel{\"o}sten Messung der pH-Konzentration},
  series = {Tagungsband: Sensoren und Messsysteme 2010},
  booktitle = {Tagungsband: Sensoren und Messsysteme 2010},
  publisher = {VDE Verlag},
  address   = {Berlin},
  isbn      = {978-3-8007-3260-9},
  pages     = {109 -- 114},
  year      = {2010},
  abstract  = {Ein lichtadressierbarer potentiometrischer Sensor (LAPS) kann die Konzentration eines oder mehrerer Analyten ortsaufgel{\"o}st auf der Sensoroberfl{\"a}che nachweisen. Dazu wird mit einer modulierten Lichtquelle die Halbleiterstruktur des zu untersuchenden Bereiches angeregt und ein entsprechender Photostrom ausgelesen. Durch gleichzeitige Anregung mehrere Bereiche durch Lichtquellen mit unterschiedlichen Modulationsfrequenzen k{\"o}nnen diese auch zeitgleich ausgelesen werden. Mit der neuen, hier vorgestellten Ansteuerungselektronik integriert in einem "Field Programmable Gate Array" (FPGA) ist es m{\"o}glich, mehrere Leuchtquellen gleichzeitig mit unterschiedlichen, w{\"a}hrend der Laufzeit festlegbaren Frequenzen, Phasen und Lichtintensit{\"a}ten zu betreiben. Somit kann das Frequenzverhalten des Sensors untersucht und die Konzentration des Analyten {\"u}ber das Oberfl{\"a}chenpotential mit Hilfe von Strom/Spannungs-Kurven und Phase/Spannungs-Kurven bestimmt werden.},
  language  = {de}
}
@inproceedings{PoghossianWagnerSchoening2010,
  author    = {Poghossian, Arshak and Wagner, Holger and Sch{\"o}ning, Michael Josef},
  title     = {Automatisiertes „wafer level"-Testsystem zur Charakterisierung von siliziumbasierten Chemo- und Biosensoren},
  series = {Tagungsband: Sensoren und Messsysteme 2010},
  booktitle = {Tagungsband: Sensoren und Messsysteme 2010},
  publisher = {VDE Verlag},
  address   = {Berlin},
  isbn      = {978-3-8007-3260-9},
  pages     = {89 -- 92},
  year      = {2010},
  abstract  = {Es wurde ein automatisiertes, computerunterst{\"u}tztes Testsystem f{\"u}r die Funktionspr{\"u}fung und Charakterisierung von (bio-)chemischen Sensoren auf Waferebene entwickelt und in einen konventionellen Spitzenmessplatz integriert. Das System erm{\"o}glicht die Charakterisierung und Identifizierung „funktionstauglicher" Sensoren bereits auf Waferebene zwischen den einzelnen Herstellungsschritten, wodurch weitere, bisher {\"u}bliche Verarbeitungsschritte wie das Fixieren, Bonden und Verkapseln f{\"u}r die defekten oder nicht funktionstauglichen Sensorstrukturen entf{\"a}llt. Außerdem bietet eine speziell entworfene miniaturisierte Durchflussmesszelle die M{\"o}glichkeit, bereits auf Waferlevel die Sensitivit{\"a}t, Drift, Hysterese und Ansprechzeit der (bio-)chemischen Sensoren zu charakterisieren. Das System wurde exemplarisch mit kapazitiven, pH-sensitiven EIS- (Elektrolyt-Isolator-Silizium) Strukturen und ISFET- (ionensensitiver Feldeffekttransistor) Strukturen mit verschiedenen Geometrien und Gate-Layouts getestet.},
  language  = {de}
}
@article{RibitschHeumannKarletal.2012,
  author    = {Ribitsch, Doris and Heumann, Sonja and Karl, Wolfgang and Gerlach, Jochen and Leber, Regina and Birner-Gruenberger, Ruth and Gruber, Karl and Eiteljoerg, Inge and Remler, Peter and Siegert, Petra and Lange, Jennifer and Maurer, Karl-Heinz and Berg, Gabriele and Guebitz, G. M. and Schwab, H.},
  title     = {Extracellular serine proteases from Stenotrophomonas maltophilia: Screening, isolation and heterologous expression in E. coli},
  series = {Journal of biotechnology},
  volume    = {157},
  journal   = {Journal of biotechnology},
  number    = {1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1873-4863 (E-Journal); 0168-1656 (Print)},
  doi       = {10.1016/j.jbiotec.2011.09.025},
  pages     = {140 -- 147},
  year      = {2012},
  abstract  = {A large strain collection comprising antagonistic bacteria was screened for novel detergent proteases. Several strains displayed protease activity on agar plates containing skim milk but were inactive in liquid media. Encapsulation of cells in alginate beads induced protease production. Stenotrophomonas maltophilia emerged as best performer under washing conditions. For identification of wash-active proteases, four extracellular serine proteases called StmPr1, StmPr2, StmPr3 and StmPr4 were cloned. StmPr2 and StmPr4 were sufficiently overexpressed in E. coli. Expression of StmPr1 and StmPr3 resulted in unprocessed, insoluble protein. Truncation of most of the C-terminal domain which has been identified by enzyme modeling succeeded in expression of soluble, active StmPr1 but failed in case of StmPr3. From laundry application tests StmPr2 turned out to be a highly wash-active protease at 45 °C. Specific activity of StmPr2 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 17 ± 2 U/mg. In addition we determined the kinetic parameters and cleavage preferences of protease StmPr2.},
  language  = {en}
}
@article{KirchnerOberlaenderFriedrichetal.2010,
  author    = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Rysstad, Gunnar and Berger, J{\"o}rg and Keusgen, Michael and Sch{\"o}ning, Michael Josef},
  title     = {Realization of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry},
  series = {Procedia Engineering},
  volume    = {5},
  journal   = {Procedia Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  doi       = {10.1016/j.proeng.2010.09.098},
  pages     = {264 -- 267},
  year      = {2010},
  abstract  = {A calorimetric gas sensor is presented for the monitoring of gas-phase H2O2 at elevated temperature during sterilization processes in aseptic food industry. The sensor consists of two temperature-sensitive thin-film resistances built up on a polyimide foil with a thickness of 25 μm, which are passivated with a layer of SU-8 photo resist and catalytically activated with manganese(IV) oxide. Instead of an active heating structure, the calorimetric sensor utilizes the elevated temperature of an evaporated H2O2 aerosol. In an experimental set-up, the sensor has shown a sensitivity of 4.78 °C/(\%v/v) in a H2O2 concentration range of 0 to 10\% v/v at an evaporation temperature of 240 ∘C. Furthermore, the sensor possesses the same, unchanged sensor signal even at varied evaporation temperatures of the gas stream. The sensor characterization demonstrates the suitability of the calorimetric gas sensor for monitoring the efficiency of sterilization processes.},
  language  = {en}
}
@article{WagnerMiyamotoSchoeningetal.2010,
  author    = {Wagner, Torsten and Miyamoto, Ko-ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Novel combination of digital light processing (DLP) and light-addressable potentiometric sensors (LAPS) for flexible chemical imaging},
  series = {Procedia Engineering},
  volume    = {5},
  journal   = {Procedia Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  doi       = {10.1016/j.proeng.2010.09.161},
  pages     = {520 -- 523},
  year      = {2010},
  abstract  = {Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach of read out in a light-addressable potentiometric sensor (LAPS) with the help of a digital light processing (DLP) set-up. The DLP, known well for video projectors, consists of a mirror-array MEMS device which allows fast and flexible generation of light patterns. With the help of these light patterns the sensor surface of the LAPS device can be read out sequentially in a raster like scheme (scanning LAPS). The DLP approach has several advantages compared to conventional scanning LAPS set-ups, e.g., the spot size, the shape and the intensity of the light pointer can be changed easily and no mechanical movement is necessary, which reduces the size of the set-up and increases the stability and speed of measurement.},
  language  = {en}
}
@article{MiyamotoKanekoMatsuoetal.2010,
  author    = {Miyamoto, Ko-ichiro and Kaneko, Kazumi and Matsuo, Akira and Wagner, Torsten and Kanoh, Shin`ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo},
  title     = {Miniaturized chemical imaging sensor system using an OLED display panel},
  series = {Procedia Engineering},
  volume    = {5},
  journal   = {Procedia Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  doi       = {10.1016/j.proeng.2010.09.160},
  pages     = {516 -- 519},
  year      = {2010},
  abstract  = {The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the two-dimensional distribution of specific ions or molecules in the solution. In this study, we developed a miniaturized chemical imaging sensor system with an OLED display panel as a light source that scans the sensor plate. In the proposed configuration, the display panel is placed directly below the sensor plate and illuminates the back surface. The measured area defined by illumination can be arbitrarily customized to fit the size and the shape of the sample to be measured. The waveform of the generated photocurrent, the currentvoltage characteristics and the pH sensitivity were investigated and pH imaging with this miniaturized system was demonstrated.},
  language  = {en}
}
@article{AbouzarPedrazaSchoeningetal.2010,
  author    = {Abouzar, Maryam H. and Pedraza, A. M. and Sch{\"o}ning, Michael Josef and Poghossian, Arshak},
  title     = {Label-free DNA hybridization and denaturation detection by means of field-effect nanoplate SOI capacitors functionalized with gold nanoparticles},
  series = {Procedia Engineering},
  volume    = {5},
  journal   = {Procedia Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  doi       = {10.1016/j.proeng.2010.09.259},
  pages     = {918 -- 921},
  year      = {2010},
  abstract  = {A new approach for a label-free electrical detection of DNA hybridization and denaturation using an array of individually addressable field-effect nanoplate SOI (silicon-on-insulator) capacitors functionalized with gold nanoparticles is presented. By using a constant-capacitance measuring setup in a differential mode, signal changes of ∼110 mV and ∼70 mV have been registered after the DNA hybridization and denaturation events, respectively.},
  language  = {en}
}
@article{BohrnStuetzFleischeretal.2010,
  author    = {Bohrn, Ulrich and St{\"u}tz, Evamaria and Fleischer, Maximilian and Sch{\"o}ning, Michael Josef},
  title     = {Real-time detection of CO by eukaryotic cells},
  series = {Procedia Engineering},
  volume    = {5},
  journal   = {Procedia Engineering},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1877-7058},
  pages     = {17 -- 20},
  year      = {2010},
  abstract  = {In this contribution, we focus on the detection of toxic gases with living eukaryotic cells. A cell-based gas sensor system, able to measure the effects of direct exposure of gases to cells in real-time, was set up. Impedance data as well as oxygen consumption of Chinese hamster lung fibroblast cells (V79) were analysed upon exposure to carbon monoxide (CO). The CO (diluted in wet synthetic air) affects the cell respiration as indicated by an attenuated respiration signal after the CO exposure as well as an instant increase of the capacitive part of the impedance signal during the gas exposure.},
  language  = {en}
}
@article{HaegerProbstJaegeretal.2023,
  author    = {Haeger, Gerrit and Probst, Johanna and Jaeger, Karl-Erich and Bongaerts, Johannes and Siegert, Petra},
  title     = {Novel aminoacylases from Streptomyces griseus DSM 40236 and their recombinant production in Streptomyces lividans},
  series = {FEBS Open Bio},
  volume    = {13},
  journal   = {FEBS Open Bio},
  number    = {12},
  publisher = {Wiley},
  address   = {Hoboken, NJ},
  issn      = {2211-5463},
  doi       = {10.1002/2211-5463.13723},
  pages     = {2224 -- 2238},
  year      = {2023},
  abstract  = {Amino acid-based surfactants are valuable compounds for cosmetic formulations. The chemical synthesis of acyl-amino acids is conventionally performed by the Schotten-Baumann reaction using fatty acyl chlorides, but aminoacylases have also been investigated for use in biocatalytic synthesis with free fatty acids. Aminoacylases and their properties are diverse; they belong to different peptidase families and show differences in substrate specificity and biocatalytic potential. Bacterial aminoacylases capable of synthesis have been isolated from Burkholderia, Mycolicibacterium, and Streptomyces. Although several proteases and peptidases from S. griseus have been described, no aminoacylases from this species have been identified yet. In this study, we investigated two novel enzymes produced by S. griseus DSM 40236ᵀ . We identified and cloned the respective genes and recombinantly expressed an α-aminoacylase (EC 3.5.1.14), designated SgAA, and an ε-lysine acylase (EC 3.5.1.17), designated SgELA, in S. lividans TK23. The purified aminoacylase SgAA was biochemically characterized, focusing on its hydrolytic activity to determine temperature- and pH optima and stabilities. The aminoacylase could hydrolyze various acetyl-amino acids at the Nα -position with a broad specificity regarding the sidechain. Substrates with longer acyl chains, like lauroyl-amino acids, were hydrolyzed to a lesser extent. Purified aminoacylase SgELA specific for the hydrolysis of Nε -acetyl-L-lysine was unstable and lost its enzymatic activity upon storage for a longer period but could initially be characterized. The pH optimum of SgELA was pH 8.0. While synthesis of acyl-amino acids was not observed with SgELA, SgAA catalyzed the synthesis of lauroyl-methionine.},
  language  = {en}
}
@article{WeldenSeverinsPoghossianetal.2022,
  author    = {Welden, Melanie and Severins, Robin and Poghossian, Arshak and Wege, Christina and Bongaerts, Johannes and Siegert, Petra and Keusgen, Michael and Sch{\"o}ning, Michael Josef},
  title     = {Detection of acetoin and diacetyl by a tobacco mosaic virus-assisted field-effect biosensor},
  series = {Chemosensors},
  volume    = {10},
  journal   = {Chemosensors},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2227-9040},
  doi       = {10.3390/chemosensors10060218},
  pages     = {Artikel 218},
  year      = {2022},
  abstract  = {Acetoin and diacetyl have a major impact on the flavor of alcoholic beverages such as wine or beer. Therefore, their measurement is important during the fermentation process. Until now, gas chromatographic techniques have typically been applied; however, these require expensive laboratory equipment and trained staff, and do not allow for online monitoring. In this work, a capacitive electrolyte-insulator-semiconductor sensor modified with tobacco mosaic virus (TMV) particles as enzyme nanocarriers for the detection of acetoin and diacetyl is presented. The enzyme acetoin reductase from Alkalihalobacillus clausii DSM 8716ᵀ is immobilized via biotin-streptavidin affinity, binding to the surface of the TMV particles. The TMV-assisted biosensor is electrochemically characterized by means of leakage-current, capacitance-voltage, and constant capacitance measurements. In this paper, the novel biosensor is studied regarding its sensitivity and long-term stability in buffer solution. Moreover, the TMV-assisted capacitive field-effect sensor is applied for the detection of diacetyl for the first time. The measurement of acetoin and diacetyl with the same sensor setup is demonstrated. Finally, the successive detection of acetoin and diacetyl in buffer and in diluted beer is studied by tuning the sensitivity of the biosensor using the pH value of the measurement solution.},
  language  = {en}
}
@article{WeldenJablonskiWegeetal.2021,
  author    = {Welden, Rene and Jablonski, Melanie and Wege, Christina and Keusgen, Michael and Wagner, Patrick Hermann and Wagner, Torsten and Sch{\"o}ning, Michael Josef},
  title     = {Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase},
  series = {Biosensors},
  volume    = {11},
  journal   = {Biosensors},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-6374},
  doi       = {10.3390/bios11060171},
  pages     = {Artikel 171},
  year      = {2021},
  abstract  = {The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte's pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS.},
  language  = {en}
}
@article{WeldenPoghossianVahidpouretal.2022,
  author    = {Welden, Melanie and Poghossian, Arshak and Vahidpour, Farnoosh and Wendlandt, Tim and Keusgen, Michael and Wege, Christina and Sch{\"o}ning, Michael Josef},
  title     = {Towards multi-analyte detection with field-effect capacitors modified with tobacco mosaic virus bioparticles as enzyme nanocarriers},
  series = {Biosensors},
  volume    = {12},
  journal   = {Biosensors},
  number    = {1},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2079-6374},
  doi       = {10.3390/bios12010043},
  pages     = {Artikel 43},
  year      = {2022},
  abstract  = {Utilizing an appropriate enzyme immobilization strategy is crucial for designing enzyme-based biosensors. Plant virus-like particles represent ideal nanoscaffolds for an extremely dense and precise immobilization of enzymes, due to their regular shape, high surface-to-volume ratio and high density of surface binding sites. In the present work, tobacco mosaic virus (TMV) particles were applied for the co-immobilization of penicillinase and urease onto the gate surface of a field-effect electrolyte-insulator-semiconductor capacitor (EISCAP) with a p-Si-SiO₂-Ta₂O₅ layer structure for the sequential detection of penicillin and urea. The TMV-assisted bi-enzyme EISCAP biosensor exhibited a high urea and penicillin sensitivity of 54 and 85 mV/dec, respectively, in the concentration range of 0.1-3 mM. For comparison, the characteristics of single-enzyme EISCAP biosensors modified with TMV particles immobilized with either penicillinase or urease were also investigated. The surface morphology of the TMV-modified Ta₂O₅-gate was analyzed by scanning electron microscopy. Additionally, the bi-enzyme EISCAP was applied to mimic an XOR (Exclusive OR) enzyme logic gate.},
  language  = {en}
}