@article{KirchnerReisertPuetzetal.2012, author = {Kirchner, Patrick and Reisert, Steffen and P{\"u}tz, Patrick and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Characterisation of polymeric materials as passivation layer for calorimetric H2O2 gas sensors}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100773}, pages = {859 -- 863}, year = {2012}, abstract = {Calorimetric gas sensors for monitoring the H₂O₂ concentration at elevated temperatures in industrial sterilisation processes have been presented in previous works. These sensors are built up in form of a differential set-up of a catalytically active and passive temperature-sensitive structure. Although, various types of catalytically active dispersions have been studied, the passivation layer has to be established and therefore, chemically as well as physically characterised. In the present work, fluorinated ethylene propylene (FEP), perfluoralkoxy (PFA) and epoxy-based SU-8 photoresist as temperature-stable polymeric materials have been investigated for sensor passivation in terms of their chemical inertness against H₂O₂, their hygroscopic properties as well as their morphology. The polymeric materials were deposited via spin-coating on the temperature-sensitive structure, wherein spin-coated FEP and PFA show slight agglomerates. However, they possess a low absorption of humidity due to their hydrophobic surface, whereas the SU-8 layer has a closed surface but shows a slightly higher absorption of water. All of them were inert against gaseous H₂O₂ during the characterisation in H₂O₂ atmosphere that demonstrates their suitability as passivation layer for calorimetric H₂O₂ gas sensors.}, language = {en} } @article{NaetherEmmerichBergeretal.2006, author = {N{\"a}ther, Niko and Emmerich, R{\"u}diger and Berger, J{\"o}rg and Friedrich, Peter and Henkel, Hartmut and Schneider, Andreas and Sch{\"o}ning, Michael Josef}, title = {A novel gas-phase hydrogen peroxide sensor basing on a combined physical/chemical transduction mechanism}, series = {Nanofunctional materials, nanostructures, and novel devices for biological and chemical detection : November 27 - December 1, 2006, Boston, Massachusetts, USA ; [at the 2006 MRS Fall Meeting].}, journal = {Nanofunctional materials, nanostructures, and novel devices for biological and chemical detection : November 27 - December 1, 2006, Boston, Massachusetts, USA ; [at the 2006 MRS Fall Meeting].}, publisher = {Materials Research Soc.}, address = {Warrendale, Pa.}, isbn = {978-1-60423-407-7}, pages = {63 -- 68}, year = {2006}, language = {en} } @article{NaetherBergerEmmerichetal.2008, author = {N{\"a}ther, Niko and Berger, J{\"o}rg and Emmerich, R{\"u}diger and Friedrich, P. and Henkel, H. and Sch{\"o}ning, Michael Josef}, title = {H2O2-Konzentrationsbestimmung f{\"u}r die Prozessgasanalytik mittels eines kalorimetrischen Sensoraufbaus}, series = {Sensoren und Messsysteme 2008 : 14. Fachtagung Ludwigsburg, 11. und 12. M{\"a}rz 2008 / VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, journal = {Sensoren und Messsysteme 2008 : 14. Fachtagung Ludwigsburg, 11. und 12. M{\"a}rz 2008 / VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, publisher = {VDI-Verl.}, address = {D{\"u}sseldorf}, isbn = {978-3-18-092011-5}, pages = {783 -- 792}, year = {2008}, language = {de} } @article{TurekSchoeningKloocketal.2008, author = {Turek, Monika and Sch{\"o}ning, Michael Josef and Kloock, Joachim P. and Schubert, J{\"u}rgen and Zander, Willi and Kr{\"u}ger, Peter and Keusgen, Michael}, title = {Herstellung und Charakterisierung eines hybriden Sensorarrays auf Halbleiterbasis f{\"u}r die Umweltanalytik}, series = {Sensoren und Messsysteme 2008 : 14. Fachtagung Ludwigsburg, 11. und 12. M{\"a}rz 2008 / VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, journal = {Sensoren und Messsysteme 2008 : 14. Fachtagung Ludwigsburg, 11. und 12. M{\"a}rz 2008 / VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, publisher = {VDI-Verl.}, address = {D{\"u}sseldorf}, isbn = {978-3-18-092011-5}, pages = {803 -- 810}, year = {2008}, language = {de} } @article{NaetherBergerEmmerichetal.2007, author = {N{\"a}ther, Niko and Berger, J{\"o}rg and Emmerich, R{\"u}diger and Friedrich, Peter and Henkel, Hartmut and Schneider, Andreas and Sch{\"o}ning, Michael Josef}, title = {Entwicklung einer kalorimetrischen H2O2-Gassensoranordnung f{\"u}r die Prozessgaskontrolle}, series = {8. Dresdner Sensor-Symposium : Sensoren f{\"u}r Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme f{\"u}r die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung f{\"u}r die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.)}, journal = {8. Dresdner Sensor-Symposium : Sensoren f{\"u}r Umwelt, Klima und Sicherheit, Biosensoren und Biosysteme, Sensoren und Sensorsysteme f{\"u}r die Prozesstechnik, Trends in der Sensortechnik, Materialentwicklung f{\"u}r die Sensorik; 8. Dresdner Sensor-Symposium, 10. - 12. Dezember 2007, Dresden / Gerald Gerlach ... (Hg.)}, publisher = {TUDpress, Verl. der Wissenschaften}, address = {Dresden}, isbn = {978-3-940046-45-1}, pages = {261 -- 264}, year = {2007}, language = {de} } @article{SchoeningSchuetz2009, author = {Sch{\"o}ning, Michael Josef and Sch{\"u}tz, S.}, title = {Der K{\"a}fer/Chip-Sensor als bioelektronischer "Schn{\"u}ffler"}, series = {Bioanalytik f{\"u}r Einsteiger : [Diabetes, Drogen und DNA] / Reinhard Renneberg. Darja S{\"u}ßbier (Ill.). [Red.: Andreas Held ...]}, journal = {Bioanalytik f{\"u}r Einsteiger : [Diabetes, Drogen und DNA] / Reinhard Renneberg. Darja S{\"u}ßbier (Ill.). [Red.: Andreas Held ...]}, publisher = {Spektrum, Akad. Verl.}, address = {Heidelberg}, isbn = {978-3-8274-1831-9}, pages = {204 -- 205}, year = {2009}, language = {de} } @article{MorenoiCodinachsKloockSchoeningetal.2008, author = {Moreno i Codinachs, Lia and Kloock, Joachim P. and Sch{\"o}ning, Michael Josef and Baldi, Antoni and Ipatov, Andrey and Bratov, Andrey and Jimenez-Jorquera, Cecilia}, title = {Electronic integrated multisensor tongue applied to grape juice and wine analysis}, series = {Analyst. 133 (2008)}, journal = {Analyst. 133 (2008)}, isbn = {1364-5528}, pages = {1440 -- 1448}, year = {2008}, language = {en} } @article{KrafftFoersterHartetal.2001, author = {Krafft, B. and F{\"o}rster, Arnold and Hart, A. van der and Sch{\"a}pers, T.}, title = {Control of Aharonov-Bohm oscillations in a AlGaAs/GaAs ring by asymmetric and symmetric gate biasing}, series = {Physica E: Low-dimensional Systems and Nanostructures. 9 (2001), H. 4}, journal = {Physica E: Low-dimensional Systems and Nanostructures. 9 (2001), H. 4}, isbn = {1386-9477}, pages = {635 -- 641}, year = {2001}, language = {en} } @article{RosenauerOberstLitvinovetal.2000, author = {Rosenauer, A. and Oberst, W. and Litvinov, D. and Gerthsen, D. and F{\"o}rster, Arnold and Schmidt, R.}, title = {Structural and Chemical Investigation of In-0.6Ga0.4As Stranski-Krastanow Layers Burried in GaAs by Transmission Electron Microscopy}, series = {Physical Review B. 61 (2000), H. 12}, journal = {Physical Review B. 61 (2000), H. 12}, isbn = {1095-3795}, pages = {8276 -- 8288}, year = {2000}, language = {en} } @article{ItabashiKosakaMiyamotoetal.2013, author = {Itabashi, Akinori and Kosaka, Naoki and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {High-speed chemical imaging system based on front-side-illuminated LAPS}, series = {Sensors and actuators B: Chemical}, volume = {182}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077}, doi = {10.1016/j.snb.2013.03.016}, pages = {315 -- 321}, year = {2013}, abstract = {The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the spatial distribution of specific ions on the sensing surface. The conventional chemical imaging system based on the light-addressable potentiometric sensor (LAPS), however, required a long time to obtain a chemical image, due to the slow mechanical scan of a single light beam. For high-speed imaging, a plurality of light beams modulated at different frequencies can be employed to measure the ion concentrations simultaneously at different locations on the sensor plate by frequency division multiplex (FDM). However, the conventional measurement geometry of back-side illumination limited the bandwidth of the modulation frequency required for FDM measurement, because of the low-pass filtering characteristics of carrier diffusion in the Si substrate. In this study, a high-speed chemical imaging system based on front-side-illuminated LAPS was developed, which achieved high-speed spatiotemporal recording of pH change at a rate of 70 frames per second.}, language = {en} } @article{IkenAhlbornGerlachetal.2013, author = {Iken, Heiko and Ahlborn, K. and Gerlach, F. and Vonau, W. and Zander, W. and Schubert, J. 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{BandodkarMolinnusMirzaetal.2014, author = {Bandodkar, Amay J. and Molinnus, Denise and Mirza, Omar and Guinovart, Tomas and Windmiller, Joshua R. and Valdes-Ramirez, Gabriela and Andrade, Francisco J. and Sch{\"o}ning, Michael Josef and Wang, Joseph}, title = {Epidermal tattoo potentiometric sodium sensors with wireless signal transduction for continuous non-invasive sweat monitoring}, series = {Biosensors and bioelectronics}, volume = {54}, journal = {Biosensors and bioelectronics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4235 (E-Journal); 0956-5663 (Print)}, doi = {10.1016/j.bios.2013.11.039}, pages = {603 -- 609}, year = {2014}, abstract = {This article describes the fabrication, characterization and application of an epidermal temporary-transfer tattoo-based potentiometric sensor, coupled with a miniaturized wearable wireless transceiver, for real-time monitoring of sodium in the human perspiration. Sodium excreted during perspiration is an excellent marker for electrolyte imbalance and provides valuable information regarding an individual's physical and mental wellbeing. The realization of the new skin-worn non-invasive tattoo-like sensing device has been realized by amalgamating several state-of-the-art thick film, laser printing, solid-state potentiometry, fluidics and wireless technologies. The resulting tattoo-based potentiometric sodium sensor displays a rapid near-Nernstian response with negligible carryover effects, and good resiliency against various mechanical deformations experienced by the human epidermis. On-body testing of the tattoo sensor coupled to a wireless transceiver during exercise activity demonstrated its ability to continuously monitor sweat sodium dynamics. The real-time sweat sodium concentration was transmitted wirelessly via a body-worn transceiver from the sodium tattoo sensor to a notebook while the subjects perspired on a stationary cycle. The favorable analytical performance along with the wearable nature of the wireless transceiver makes the new epidermal potentiometric sensing system attractive for continuous monitoring the sodium dynamics in human perspiration during diverse activities relevant to the healthcare, fitness, military, healthcare and skin-care domains.}, language = {en} } @article{ReisertGeisslerFloerkeetal.2013, author = {Reisert, Steffen and Geissler, Hanno and Fl{\"o}rke, Rudolf and Weiler, Christian and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Characterisation of aseptic sterilisation processes using an electronic nose}, series = {International journal of nanotechnology}, volume = {Vol. 10}, journal = {International journal of nanotechnology}, number = {No. 5-7}, publisher = {Inderscience Enterprises}, address = {Gen{\`e}ve}, issn = {1475-7435 (Print) 7141-8151 (Online)}, pages = {470 -- 484}, year = {2013}, language = {en} } @article{MiyamotoHirayamaWagneretal.2013, author = {Miyamoto, Ko-ichiro and Hirayama, Yuji and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Visualization of enzymatic reaction in a microfluidic channel using chemical imaging sensor}, series = {Electrochimica acta}, journal = {Electrochimica acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3859 (E-Journal); 0013-4686 (Print)}, pages = {Publ. online}, year = {2013}, language = {en} } @article{SabitovaEbertLenzetal.2013, author = {Sabitova, A. and Ebert, Ph. and Lenz, A. and Schaafhausen, S. and Ivanova, L. and D{\"a}hne, M. and Hoffmann, A. and Dunin-Borkowski, R. E. and F{\"o}rster, Arnold and Grandidier, B. and Eisele, H.}, title = {Intrinsic bandgap of cleaved ZnO(112¯0) surfaces}, series = {Applied physics letters}, volume = {Vol. 102}, journal = {Applied physics letters}, issn = {1077-3118 (E-Journal); 0003-6951 (Print)}, pages = {021608}, year = {2013}, language = {en} } @article{HeineHerrmannSelmeretal.2014, author = {Heine, A. and Herrmann, G. and Selmer, Thorsten and Terwesten, F. and Buckel, W. and Reuter, K.}, title = {High resolution crystal structure of clostridium propionicum β-Alanyl-CoA:Ammonia Lyase, a new member of the "Hot Dog Fold" protein superfamily}, series = {Proteins}, volume = {82}, journal = {Proteins}, number = {9}, publisher = {Wiley-Liss}, address = {New York}, issn = {1097-0134 (E-Journal); 0887-3585 (Print)}, doi = {10.1002/prot.24557}, pages = {2041 -- 2053}, year = {2014}, abstract = {Clostridium propionicum is the only organism known to ferment β-alanine, a constituent of coenzyme A (CoA) and the phosphopantetheinyl prosthetic group of holo-acyl carrier protein. The first step in the fermentation is a CoA-transfer to β-alanine. Subsequently, the resulting β-alanyl-CoA is deaminated by the enzyme β-alanyl-CoA:ammonia lyase (Acl) to reversibly form ammonia and acrylyl-CoA. We have determined the crystal structure of Acl in its apo-form at a resolution of 0.97 {\AA} as well as in complex with CoA at a resolution of 1.59 {\AA}. The structures reveal that the enyzme belongs to a superfamily of proteins exhibiting a so called "hot dog fold" which is characterized by a five-stranded antiparallel β-sheet with a long α-helix packed against it. The functional unit of all "hot dog fold" proteins is a homodimer containing two equivalent substrate binding sites which are established by the dimer interface. In the case of Acl, three functional dimers combine to a homohexamer strongly resembling the homohexamer formed by YciA-like acyl-CoA thioesterases. Here, we propose an enzymatic mechanism based on the crystal structure of the Acl·CoA complex and molecular docking. Proteins 2014; 82:2041-2053. © 2014 Wiley Periodicals, Inc.}, language = {en} } @article{TakenagaBiselliSchnitzleretal.2014, author = {Takenaga, Shoko and Biselli, Manfred and Schnitzler, Thomas and {\"O}hlschl{\"a}ger, Peter and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Toward multi-analyte bioarray sensors: LAPS-based on-chip determination of a Michaelis-Menten-like kinetics for cell culturing}, series = {Physica status solidi A : Applications and materials science}, volume = {211}, journal = {Physica status solidi A : Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330464}, pages = {1410 -- 1415}, year = {2014}, abstract = {The metabolic activity of Chinese hamster ovary (CHO) cells was observed using a light-addressable potentiometric sensor (LAPS). The dependency toward different glucose concentrations (17-200 mM) follows a Michaelis-Menten kinetics trajectory with Kₘ = 32.8 mM, and the obtained Kₘ value in this experiment was compared with that found in literature. In addition, the pH shift induced by glucose metabolism of tumor cells transfected with the HPV-16 genome (C3 cells) was successfully observed. These results indicate the possibility to determine the tumor cells metabolism with a LAPS-based measurement device.}, language = {en} } @article{OberlaenderKirchnerBoyenetal.2014, author = {Oberl{\"a}nder, Jan and Kirchner, Patrick and Boyen, Hans-Gerd and Sch{\"o}ning, Michael Josef}, title = {Detection of hydrogen peroxide vapor by use of manganese(IV) oxide as catalyst for calorimetric gas sensors}, series = {Physica status solidi A: Applications and materials science}, volume = {211}, journal = {Physica status solidi A: Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330359}, pages = {1372 -- 1376}, year = {2014}, abstract = {In this work, the catalyst manganese(IV) oxide (MnO2), of calorimetric gas sensors (to monitor the sterilization agent vaporized hydrogen peroxide) has been investigated in more detail. Chemical analyses by means of X-ray-induced photoelectron spectroscopy have been performed to unravel the surface chemistry prior and after exposure to hydrogen peroxide vapor at elevated temperature, as applied in the sterilization processes of beverage cartons. The surface characterization reveals a change in oxidation states of the metal oxide catalyst after exposure to hydrogen peroxide. Additionally, a cleaning effect of the catalyst, which itself is attached to the sensor surface by means of a polymer interlayer, could be observed.}, language = {en} } @article{GuoMiyamotoWagneretal.2014, author = {Guo, Yuanyuan and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Theoretical study and simulation of light-addressable potentiometric sensors}, series = {Physica status solidi (A) : applications and materials}, volume = {211}, journal = {Physica status solidi (A) : applications and materials}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0031-8965}, doi = {10.1002/pssa.201330354}, pages = {1467 -- 1472}, year = {2014}, abstract = {The light-addressable potentiometric sensor (LAPS) is a semiconductor-based potentiometric sensor using a light probe with an ability of detecting the concentration of biochemical species in a spatially resolved manner. As an important biomedical sensor, research has been conducted to improve its performance, for instance, to realize high-speed measurement. In this work, the idea of facilitating the device-level simulation, instead of using an equivalent-circuit model, is presented for detailed analysis and optimization of the performance of the LAPS. Both carrier distribution and photocurrent response have been simulated to provide new insight into both amplitude-mode and phase-mode operations of the LAPS. Various device parameters can be examined to effectively design and optimize the LAPS structures and setups for enhanced performance.}, language = {en} } @article{MartinezJakobTuetal.2013, author = {Martinez, Ronny and Jakob, Felix and Tu, Ran and Siegert, Petra and Maurer, Karl-Heinz and Schwaneberg, Ulrich}, title = {Increasing activity and thermal resistance of Bacillus gibsonii alkaline protease (BgAP) by directed evolution}, series = {Biotechnology and bioengineering}, volume = {Vol. 110}, journal = {Biotechnology and bioengineering}, number = {Iss. 3}, publisher = {Wiley}, address = {Weinheim}, issn = {1097-0290 (E-Journal); 0006-3592 (Print); 0368-1467 (Print)}, pages = {711 -- 720}, year = {2013}, language = {en} } @article{RibitschHeumannKarletal.2012, author = {Ribitsch, D. and Heumann, S. and Karl, W. and Gerlach, J. and Leber, R. and Birner-Gruenberger, R. and Gruber, K. and Eiteljoerg, I. and Remler, P. and Siegert, Petra and Lange, J. and Maurer, Karl-Heinz and Berg, G. 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{RibitschKarlBirnerGruenbergeretal.2010, author = {Ribitsch, D. and Karl, W. and Birner-Gruenberger, R. and Gruber, K. and Eiteljoerg, I. and Remler, P. and Wieland, S. and Siegert, Petra and Maurer, Karl-Heinz and Schwab, H.}, title = {C-terminal truncation of a metagenome-derived detergent protease for effective expression in E. coli}, series = {Journal of biotechnology}, volume = {150}, journal = {Journal of biotechnology}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4863 (E-Journal); 0168-1656 (Print)}, doi = {10.1016/j.jbiotec.2010.09.947}, pages = {408 -- 416}, year = {2010}, abstract = {Recently, a new alkaline protease named HP70 showing highest homology to extracellular serine proteases of Stenotrophomonas maltophilia and Xanthomonas campestris was found in the course of a metagenome screening for detergent proteases (Niehaus et al., submitted for publication). Attempts to efficiently express the enzyme in common expression hosts had failed. This study reports on the realization of overexpression in Escherichia coli after structural modification of HP70. Modelling of HP70 resulted in a two-domain structure, comprising the catalytic domain and a C-terminal domain which includes about 100 amino acids. On the basis of the modelled structure the enzyme was truncated by deletion of most of the C-terminal domain yielding HP70-C477. This structural modification allowed effective expression of active enzyme using E. coli BL21-Gold as the host. Specific activity of HP70-C477 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 30 ± 5 U/mg compared to 8 ± 1 U/mg of the native enzyme. HP70-C477 was most active at 40 °C and pH 7-11; these conditions are prerequisite for a potential application as detergent enzyme. Determination of kinetic parameters at 40 °C and pH = 9.5 resulted in KM = 0.23 ± 0.01 mM and kcat = 167.5 ± 3.6 s⁻¹. MS-analysis of peptide fragments obtained from incubation of HP70 and HP70-C477 with insulin B indicated that the C-terminal domain influences the cleavage preferences of the enzyme. Washing experiments confirmed the high potential of HP70-C477 as detergent protease.}, language = {en} } @article{SiegertMcLeishBaumannetal.2005, author = {Siegert, Petra and McLeish, Michael J. and Baumann, Martin and Iding, Hans and Kneen, Malea M. and Kenyon, George L. and Pohl, Martina}, title = {Exchanging the substrate specificities of pyruvate decarboxylase from Zymomonas mobilis and benzoylformate decarboxylase from Pseudomonas putida}, series = {Protein engineering, design, and selection : peds}, volume = {Vol. 18}, journal = {Protein engineering, design, and selection : peds}, number = {Iss. 7}, issn = {1460-213X (E-Journal); 1741-0134 (E-Journal); 0269-2139 (Print); 1741-0126 (Print)}, pages = {345 -- 357}, year = {2005}, language = {en} } @article{GuoSekiMiyamotoetal.2014, author = {Guo, Yuanyuan and Seki, Kosuke and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Novel photoexcitation method for light-addressable potentiometric sensor with higher spatial resolution}, series = {Applied physics express : APEX}, volume = {7}, journal = {Applied physics express : APEX}, number = {6}, publisher = {IOP}, address = {Bristol}, issn = {1882-0786 (E-Journa); 1882-0778 (Print)}, doi = {10.7567/APEX.7.067301}, pages = {067301-4}, year = {2014}, abstract = {A novel photoexcitation method for the light-addressable potentiometric sensor (LAPS) is proposed to achieve a higher spatial resolution of chemical images. The proposed method employs a combined light source that consists of a modulated light probe, which generates the alternating photocurrent signal, and a ring of constant illumination surrounding it. The constant illumination generates a sheath of carriers with increased concentration which suppresses the spread of photocarriers by enhanced recombination. A device simulation was carried out to verify the effect of constant illumination on the spatial resolution, which demonstrated that a higher spatial resolution can be obtained.}, language = {en} } @article{WhiteheadOehlschlaegerAlmajhdietal.2014, author = {Whitehead, Mark and {\"O}hlschl{\"a}ger, Peter and Almajhdi, Fahad N. and Alloza, Leonor and Marz{\´a}bal, Pablo and Meyers, Ann E. and Hitzeroth, Inga I. and Rybicki, Edward P.}, title = {Human papillomavirus (HPV) type 16 E7 protein bodies cause tumour regression in mice}, series = {BMC cancer}, journal = {BMC cancer}, number = {14:367}, publisher = {BioMed Central}, address = {London}, issn = {1471-2407}, doi = {10.1186/1471-2407-14-367}, pages = {1 -- 15}, year = {2014}, language = {en} } @article{WagnerDollSchoening2014, author = {Wagner, Patrick and Doll, Theodor and Sch{\"o}ning, Michael Josef}, title = {Engineering of functional interfaces / Patrick Wagner ; Theodor Doll ; Michael J. Sch{\"o}ning (eds.)}, series = {Physica status solidi (A) : Applications and materials science}, volume = {211}, journal = {Physica status solidi (A) : Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E-Book); 1862-6319 (E-Book); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201470241}, pages = {1339 -- 1339}, year = {2014}, language = {en} } @article{OberlaenderBrommWendeleretal.2015, author = {Oberl{\"a}nder, Jan and Bromm, Alexander and Wendeler, Luisa and Iken, Heiko and Palomar Duran, Marlena and Greeff, Anton and Kirchner, Patrick and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Towards a biosensor to monitor the sterilisation efficiency of aseptic filling machines}, 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.201431900}, pages = {1299 -- 1305}, year = {2015}, abstract = {Sterilisation processes are compulsory in medicine, pharmacy, and food industries to prevent infections of consumers and microbiological contaminations of products. Monitoring the sterilisation by conventional microbiological methods is time- and lab-consuming. To overcome this problem, in this work a novel biosensor has been proposed. The sensor enables a fast method to evaluate sterilisation processes. By means of thin-film technology the sensor's transducer structures in form of IDEs (interdigitated electrodes) have been fabricated on a silicon substrate. Physical characterisation of the developed sensor was done by AFM, SEM, and profilometry. Impedance analyses were conducted for the electrical characterisation. As microbiological layer spores of B. atrophaeus have been immobilised on the sensing structure; spores of this type are a well-known sterilisation test organism. Impedance measurements at a fixed frequency over time were performed to monitor the immobilisation process. A sterilisation process according to aseptic filling machines was applied to demonstrate the sensor functionality. After both, immobilisation and sterilisation, a change in impedance could successfully be detected.}, language = {en} } @article{JildehWagnerSchoeningetal.2015, author = {Jildeh, Zaid B. and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Pieper, Martin}, title = {Simulating the electromagnetic-thermal treatment of thin aluminium layers for adhesion improvement}, series = {Physica status solidi (a)}, volume = {Vol. 212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431893}, pages = {1234 -- 1241}, year = {2015}, abstract = {A composite layer material used in packaging industry is made from joining layers of different materials using an adhesive. An important processing step in the production of aluminium-containing composites is the surface treatment and consequent coating of adhesive material on the aluminium surface. To increase adhesion strength between aluminium layer and the adhesive material, the foil is heat treated. For efficient heating, induction heating was considered as state-of-the-art treatment process. Due to the complexity of the heating process and the unpredictable nature of the heating source, the control of the process is not yet optimised. In this work, a finite element analysis of the process was established and various process parameters were studied. The process was simplified and modelled in 3D. The numerical model contains an air domain, an aluminium layer and a copper coil fitted with a magnetic field concentrating material. The effect of changing the speed of the aluminium foil (or rolling speed) was studied with the change of the coil current. Statistical analysis was used for generating a general control equation of coil current with changing rolling speed.}, language = {en} } @article{PilasIkenSelmeretal.2015, author = {Pilas, Johanna and Iken, Heiko and Selmer, Thorsten and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Development of a multi-parameter sensor chip for the simultaneous detection of organic compounds in biogas processes}, 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.201431894}, pages = {1306 -- 1312}, year = {2015}, abstract = {An enzyme-based multi-parameter biosensor is developed for monitoring the concentration of formate, d-lactate, and l-lactate in biological samples. The sensor is based on the specific dehydrogenation by an oxidized β-nicotinamide adenine dinucleotide (NAD+)-dependent dehydrogenase (formate dehydrogenase, d-lactic dehydrogenase, and l-lactic dehydrogenase, respectively) in combination with a diaphorase from Clostridium kluyveri (EC 1.8.1.4). The enzymes are immobilized on a platinum working electrode by cross-linking with glutaraldehyde (GA). The principle of the determination scheme in case of l-lactate is as follows: l-lactic dehydrogenase (l-LDH) converts l-lactate into pyruvate by reaction with NAD+. In the presence of hexacyanoferrate(III), the resulting reduced β-nicotinamide adenine dinucleotide (NADH) is then regenerated enzymatically by diaphorase. The electrochemical detection is based on the current generated by oxidation of hexacyanoferrate(II) at an applied potential of +0.3 V vs. an Ag/AgCl reference electrode. The biosensor will be electrochemically characterized in terms of linear working range and sensitivity. Additionally, the successful practical application of the sensor is demonstrated in an extract from maize silage.}, language = {en} } @article{BreuerRaueKirschbaumetal.2015, author = {Breuer, Lars and Raue, Markus and Kirschbaum, M. and Mang, Thomas and Sch{\"o}ning, Michael Josef and Thoelen, R. and Wagner, Torsten}, title = {Light-controllable polymeric material based on temperature-sensitive hydrogels with incorporated graphene oxide}, 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.201431944}, pages = {1368 -- 1374}, year = {2015}, abstract = {Poly(N-isopropylacrylamide) (PNIPAAm) hydrogel films with incorporated graphene oxide (GO) were developed and tested as light-stimulated actuators. GO dispersions were synthesized via Hummers method and characterized toward their optical properties and photothermal energy conversion. The hydrogels were prepared by means of photopolymerization. In addition, the influence of GO within the hydrogel network on the lower critical solution temperature (LCST) was investigated by differential scanning calorimetry (DSC). The optical absorbance and the response to illumination were determined as a function of GO concentration for thin hydrogel films. A proof of principle for the stimulation with light was performed.}, language = {en} } @article{SchiffelsSelmer2015, author = {Schiffels, Johannes and Selmer, Thorsten}, title = {A flexible toolbox to study protein-assisted metalloenzyme assembly in vitro}, series = {Biotechnology and Bioengineering}, volume = {112}, journal = {Biotechnology and Bioengineering}, number = {11}, publisher = {Wiley}, address = {Weinheim}, issn = {1097-0290}, doi = {10.1002/bit.25658}, pages = {2360 -- 2372}, year = {2015}, language = {en} } @article{DantismTakenagaWagneretal.2015, author = {Dantism, S. and Takenaga, S. and Wagner, P. and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Light-addressable Potentiometric Sensor (LAPS) Combined with Multi-chamber Structures to Investigate the Metabolic Activity of Cells}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.647}, pages = {384 -- 387}, year = {2015}, abstract = {LAPS are field-effect-based potentiometric sensors which are able to monitor analyte concentrations in a spatially resolved manner. Hence, a LAPS sensor system is a powerful device to record chemical imaging of the concentration of chemical species in an aqueous solution, chemical reactions, or the growth of cell colonies on the sensor surface, to record chemical images. In this work, multi-chamber 3D-printed structures made out of polymer (PP-ABS) were combined with LAPS chips to analyse differentially and simultaneously the metabolic activity of Escherichia coli K12 and Chinese hamster ovary (CHO) cells, and the responds of those cells to the addition of glucose solution.}, language = {en} } @article{PilasMarianoKeusgenetal.2015, author = {Pilas, Johanna and Mariano, K. and Keusgen, M. and Selmer, Thorsten and Sch{\"o}ning, Michael Josef}, title = {Optimization of an Enzyme-based Multi-parameter Biosensor for Monitoring Biogas Processes}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.702}, pages = {532 -- 535}, year = {2015}, language = {en} } @article{MiyamotoBingWagneretal.2015, author = {Miyamoto, Ko-ichiro and Bing, Yu and Wagner, Torsten and Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef}, title = {Visualization of Defects on a Cultured Cell Layer by Utilizing Chemical Imaging Sensor}, series = {Procedia Engineering}, volume = {120}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2015.08.806}, pages = {936 -- 939}, year = {2015}, abstract = {The chemical imaging sensor is a field-effect sensor which is able to visualize both the distribution of ions (in LAPS mode) and the distribution of impedance (in SPIM mode) inthe sample. In this study, a novel wound-healing assay is proposed, in which the chemical imaging sensor operated in SPIM mode is applied to monitor the defect of a cell layer brought into proximity of the sensing surface.A reduced impedance inside the defect, which was artificially formed ina cell layer, was successfully visualized in a photocurrent image.}, language = {en} } @article{BrahmaMusioIsmayilovaetal.2015, author = {Brahma, Aischarya and Musio, Biagia and Ismayilova, Uliviya and Nikbin, Nikzad and Kamptmann, Sonja B. and Siegert, Petra and Jeromin, G{\"u}nter Erich and Ley, Steven and Pohl, Martina}, title = {An orthogonal biocatalytic approach for the safe generation and use of HCN in a multi-step continuous preparation of chiral O-acetylcyanohydrins}, series = {Synlett}, journal = {Synlett}, number = {Publ. online 29.09.2015}, publisher = {Thieme}, address = {Stuttgart}, issn = {0936-5214 (Print) ; 1437-2096 (e-Journal)}, doi = {10.1055/s-0035-1560644}, year = {2015}, language = {de} } @article{OberlaenderJildehKirchneretal.2015, author = {Oberl{\"a}nder, Jan and Jildeh, Zaid B. and Kirchner, Patrick and Wendeler, Luisa and Bromm, Alexander and Iken, Heiko and Wagner, Patrick and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Study of Interdigitated Electrode Arrays Using Experiments and Finite Element Models for the Evaluation of Sterilization Processes}, series = {Sensors}, volume = {15}, journal = {Sensors}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s151026115}, pages = {26115 -- 26127}, year = {2015}, abstract = {In this work, a sensor to evaluate sterilization processes with hydrogen peroxide vapor has been characterized. Experimental, analytical and numerical methods were applied to evaluate and study the sensor behavior. The sensor set-up is based on planar interdigitated electrodes. The interdigitated electrode structure consists of 614 electrode fingers spanning over a total sensing area of 20 mm2. Sensor measurements were conducted with and without microbiological spores as well as after an industrial sterilization protocol. The measurements were verified using an analytical expression based on a first-order elliptical integral. A model based on the finite element method with periodic boundary conditions in two dimensions was developed and utilized to validate the experimental findings.}, language = {en} } @article{ArreolaMaetzkowDuranetal.2016, author = {Arreola, Julio and M{\"a}tzkow, Malte and Dur{\´a}n, Marlena Palomar and Greeff, Anton and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Optimization of the immobilization of bacterial spores on glass substrates with organosilanes}, series = {Physica status solidi (A) : Applications and materials science}, volume = {213}, journal = {Physica status solidi (A) : Applications and materials science}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201532914}, pages = {1463 -- 1470}, year = {2016}, abstract = {Spores can be immobilized on biosensors to function as sensitive recognition elements. However, the immobilization can affect the sensitivity and reproducibility of the sensor signal. In this work, three different immobilization strategies with organosilanes were optimized and characterized to immobilize Bacillus atrophaeus spores on glass substrates. Five different silanization parameters were investigated: nature of the solvent, concentration of the silane, silanization time, curing process, and silanization temperature. The resulting silane layers were resistant to a buffer solution (e.g., Ringer solution) with a polysorbate (e.g., Tween®80) and sonication.}, language = {en} } @article{MiyamotoItabashiWagneretal.2014, author = {Miyamoto, Ko-ichiro and Itabashi, Akinori and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {High-speed chemical imaging inside a microfluidic channel}, series = {Sensors and actuators. B: Chemical}, volume = {194}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2013.12.090}, pages = {521 -- 527}, year = {2014}, abstract = {In this study, a high-speed chemical imaging system was developed for visualization of the interior of a microfluidic channel. A microfluidic channel was constructed on the sensor surface of the light-addressable potentiometric sensor (LAPS), on which the ion concentrations could be measured in parallel at up to 64 points illuminated by optical fibers. The temporal change of pH distribution inside the microfluidic channel was recorded at a maximum rate of 100 frames per second (fps). The high frame rate allowed visualization of moving interfaces and plugs in the channel even at a flow velocity of 111 mm/s, which suggests the feasibility of plug-based microfluidic devices for flow-injection analysis (FIA).}, language = {en} } @article{SiqueiraMolinnusBegingetal.2014, author = {Siqueira, Jose R. and Molinnus, Denise and Beging, Stefan and Sch{\"o}ning, Michael Josef}, title = {Incorporating a hybrid urease-carbon nanotubes sensitive nanofilm on capacitive field-effect sensors for urea detection}, series = {Analytical chemistry}, volume = {86}, journal = {Analytical chemistry}, number = {11}, publisher = {ACS Publications}, address = {Columbus}, issn = {1520-6882 (E-Journal); 0003-2700 (Print); 0096-4484 (Print)}, doi = {10.1021/ac500458s}, pages = {5370 -- 5375}, year = {2014}, abstract = {The ideal combination among biomolecules and nanomaterials is the key for reaching biosensing units with high sensitivity. The challenge, however, is to find out a stable and sensitive film architecture that can be incorporated on the sensor's surface. In this paper, we report on the benefits of incorporating a layer-by-layer (LbL) nanofilm of polyamidoamine (PAMAM) dendrimer and carbon nanotubes (CNTs) on capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensors for detecting urea. Three sensor arrangements were studied in order to investigate the adequate film architecture, involving the LbL film with the enzyme urease: (i) urease immobilized directly onto a bare EIS [EIS-urease] sensor; (ii) urease atop the LbL film over the EIS [EIS-(PAMAM/CNT)-urease] sensor; and (iii) urease sandwiched between the LbL film and another CNT layer [EIS-(PAMAM/CNT)-urease-CNT]. The surface morphology of all three urea-based EIS biosensors was investigated by atomic force microscopy (AFM), while the biosensing abilities were studied by means of capacitance-voltage (C/V) and dynamic constant-capacitance (ConCap) measureaments at urea concentrations ranging from 0.1 mM to 100 mM. The EIS-urease and EIS-(PAMAM/CNT)-urease sensors showed similar sensitivity (∼18 mV/decade) and a nonregular signal behavior as the urea concentration increased. On the other hand, the EIS-(PAMAM/CNT)-urease-CNT sensor exhibited a superior output signal performance and higher sensitivity of about 33 mV/decade. The presence of the additional CNT layer was decisive to achieve a urea based EIS sensor with enhanced properties. Such sensitive architecture demonstrates that the incorporation of an adequate hybrid enzyme-nanofilm as sensing unit opens new prospects for biosensing applications using the field-effect sensor platform.}, language = {en} } @article{GuoMiyamotoWagneretal.2014, author = {Guo, Yuanyuan and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Device simulation of the light-addressable potentiometric sensor for the investigation of the spatial resolution}, series = {Sensors and actuators B: Chemical}, volume = {204}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.08.016}, pages = {659 -- 665}, year = {2014}, abstract = {As a semiconductor-based electrochemical sensor, the light-addressable potentiometric sensor (LAPS) can realize two dimensional visualization of (bio-)chemical reactions at the sensor surface addressed by localized illumination. Thanks to this imaging capability, various applications in biochemical and biomedical fields are expected, for which the spatial resolution is critically significant. In this study, therefore, the spatial resolution of the LAPS was investigated in detail based on the device simulation. By calculating the spatiotemporal change of the distributions of electrons and holes inside the semiconductor layer in response to a modulated illumination, the photocurrent response as well as the spatial resolution was obtained as a function of various parameters such as the thickness of the Si substrate, the doping concentration, the wavelength and the intensity of illumination. The simulation results verified that both thinning the semiconductor substrate and increasing the doping concentration could improve the spatial resolution, which were in good agreement with known experimental results and theoretical analysis. More importantly, new findings of interests were also obtained. As for the dependence on the wavelength of illumination, it was found that the known dependence was not always the case. When the Si substrate was thick, a longer wavelength resulted in a higher spatial resolution which was known by experiments. When the Si substrate was thin, however, a longer wavelength of light resulted in a lower spatial resolution. This finding was explained as an effect of raised concentration of carriers, which reduced the thickness of the space charge region. The device simulation was found to be helpful to understand the relationship between the spatial resolution and device parameters, to understand the physics behind it, and to optimize the device structure and measurement conditions for realizing higher performance of chemical imaging systems.}, language = {en} } @article{ReisertGeisslerWeileretal.2015, author = {Reisert, Steffen and Geissler, H. and Weiler, C. and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Multiple sensor-type system for monitoring the microbicidal effectiveness of aseptic sterilisation processes}, series = {Food control}, volume = {47}, journal = {Food control}, issn = {1873-7129 (E-Journal); 0956-7135 (Print)}, doi = {10.1016/j.foodcont.2014.07.063}, pages = {615 -- 622}, year = {2015}, abstract = {The present work describes a novel multiple sensor-type system for the real-time analysis of aseptic sterilisation processes employing gaseous hydrogen peroxide (H2O2) as a sterilant. The inactivation kinetics of Bacillus atrophaeus by gaseous H2O2 have been investigated by means of a methodical calibration experiment, taking into account the process variables H2O2 concentration, humidity and gas temperature. It has been found that the microbicidal effectiveness at H2O2 concentrations above 2\% v/v is largely determined by the concentration itself, while at lower H2O2 concentrations, the gas temperature and humidity play a leading role. Furthermore, the responses of different types of gas sensors towards the influencing factors of the sterilisation process have been analysed within the same experiment. Based on a correlation established between the inactivation kinetics and the sensor responses, a calorimetric H2O2 sensor and a metal-oxide semiconductor (MOX) sensor have been identified as possible candidates for monitoring the microbicidal effectiveness of aseptic sterilisation processes employing gaseous H2O2. Therefore, two linear models that describe the relationship between sensor response and microbicidal effectiveness have been proposed.}, language = {en} } @article{KhaydukovaZadorozhnayaKirsanovetal.2014, author = {Khaydukova, M. M. and Zadorozhnaya, O. A. and Kirsanov, D. O. and Iken, Heiko and Rolka, David and Sch{\"o}ning, Michael Josef and Babain, V. A. and Vlasov, Yu. G. and Legin, A. V.}, title = {Multivariate processing of atomic-force microscopy images for detection of the response of plasticized polymeric membranes}, series = {Russian journal of applied chemistry}, volume = {87}, journal = {Russian journal of applied chemistry}, number = {3}, publisher = {Springer}, address = {Dordrecht}, issn = {1608-3296 (E-Journal); 1070-4272 (Print)}, doi = {10.1134/S1070427214030112}, pages = {307 -- 314}, year = {2014}, abstract = {The possibility of using the atomic-force microscopy as a method for detection of the analytical signal from plasticized polymeric sensor membranes was analyzed. The surfaces of cadmium-selective membranes based on two polymeric matrices were examined. The digital images were processed with multivariate image analysis techniques. A correlation was found between the surface profile of an ion-selective membrane and the concentration of the ion in solution.}, language = {en} } @article{YoshinobuMiyamotoWagneretal.2015, author = {Yoshinobu, Tatsuo and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Recent developments of chemical imaging sensor systems based on the principle of the light-addressable potentiometric sensor}, series = {Sensors and actuators B: Chemical}, volume = {207, Part B}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.09.002}, pages = {926 -- 932}, year = {2015}, abstract = {The light-addressable potentiometric sensor (LAPS) is an electrochemical sensor with a field-effect structure to detect the variation of the Nernst potential at its sensor surface, the measured area on which is defined by illumination. Thanks to this light-addressability, the LAPS can be applied to chemical imaging sensor systems, which can visualize the two-dimensional distribution of a particular target ion on the sensor surface. Chemical imaging sensor systems are expected to be useful for analysis of reaction and diffusion in various electrochemical and biological samples. Recent developments of LAPS-based chemical imaging sensor systems, in terms of the spatial resolution, measurement speed, image quality, miniaturization and integration with microfluidic devices, are summarized and discussed.}, language = {en} } @article{MuribYeapMartensetal.2015, author = {Murib, M. S. and Yeap, W. S. and Martens, D. and Liu, X. and Bienstman, P. and Fahlman, M. and Sch{\"o}ning, Michael Josef and Michiels, L. and Haenen, K. and Serpeng{\"u}zel, A. and Wagner, Patrick}, title = {Photonic studies on polymer-coated sapphire-spheres : a model system for biological ligands}, series = {Sensors and actuators A: Physical}, volume = {222}, journal = {Sensors and actuators A: Physical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3069 (E-Journal); 0924-4247 (Print)}, doi = {10.1016/j.sna.2014.11.024}, pages = {212 -- 219}, year = {2015}, abstract = {In this study we show an optical biosensor concept, based on elastic light scattering from sapphire microspheres. Transmitted and elastic scattering intensity of the microspheres (radius 500 μm, refractive index 1.77) on an optical fiber half coupler is analyzed at 1510 nm. The 0.43 nm angular mode spacing of the resonances is comparable to the angular mode spacing value estimated using the optical size of the microsphere. The spectral linewidths of the resonances are in the order of 0.01 nm, which corresponds to quality factors of approximately 105. A polydopamine layer is used as a functionalizing agent on sapphire microspherical resonators in view of biosensor implementation. The varying layer thickness on the microsphere is determined as a function of the resonance wavelength shift. It is shown that polymer functionalization has a minor effect on the quality factor. This is a promising step toward the development of an optical biosensor.}, language = {en} } @article{MiyamotoSekiWagneretal.2014, author = {Miyamoto, K. and Seki, K. and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, T.}, title = {Enhancement of the spatial resolution of the chemical imaging sensor by a hybrid fiber-optic illumination}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.563}, pages = {612 -- 615}, year = {2014}, abstract = {The chemical imaging sensor, which is based on the principle of the light-addressable potentiometric sensor (LAPS), is a powerful tool to visualize the spatial distribution of chemical species on the sensor surface. The spatial resolution of this sensor depends on the diffusion of photocarriers excited by a modulated light. In this study, a novel hybrid fiber-optic illumination was developed to enhance the spatial resolution. It consists of a modulated light probe to generate a photocurrent signal and a ring of constant light, which suppresses the lateral diffusion of minority carriers excited by the modulated light. It is demonstrated that the spatial resolution was improved from 92 μm to 68 μm.}, language = {en} } @article{AlmajhdiSengerAmeretal.2014, author = {Almajhdi, Fahad N. and Senger, Tilo and Amer, Haitham M. and Gissmann, Lutz and {\"O}hlschl{\"a}ger, Peter}, title = {Design of a highly effective therapeutic HPV16 E6/E7-specific DNA vaccine: optimization by different ways of sequence rearrangements (Shuffling)}, series = {PLOS one}, volume = {11}, journal = {PLOS one}, number = {9}, publisher = {PLOS}, address = {San Francisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0113461}, pages = {e113461}, year = {2014}, abstract = {Persistent infection with the high-risk Human Papillomavirus type 16 (HPV 16) is the causative event for the development of cervical cancer and other malignant tumors of the anogenital tract and of the head and neck. Despite many attempts to develop therapeutic vaccines no candidate has entered late clinical trials. An interesting approach is a DNA based vaccine encompassing the nucleotide sequence of the E6 and E7 viral oncoproteins. Because both proteins are consistently expressed in HPV infected cells they represent excellent targets for immune therapy. Here we report the development of 8 DNA vaccine candidates consisting of differently rearranged HPV-16 E6 and E7 sequences within one molecule providing all naturally occurring epitopes but supposedly lacking transforming activity. The HPV sequences were fused to the J-domain and the SV40 enhancer in order to increase immune responses. We demonstrate that one out of the 8 vaccine candidates induces very strong cellular E6- and E7- specific cellular immune responses in mice and, as shown in regression experiments, efficiently controls growth of HPV 16 positive syngeneic tumors. This data demonstrates the potential of this vaccine candidate to control persistent HPV 16 infection that may lead to malignant disease. It also suggests that different sequence rearrangements influence the immunogenecity by an as yet unknown mechanism.}, language = {en} } @article{SchoeningBaecker2012, author = {Sch{\"o}ning, Michael Josef and B{\"a}cker, Matthias}, title = {Chip-basierte Sensoren f{\"u}r die Biotechnik}, volume = {13}, number = {2}, publisher = {BIOCOM}, address = {Berlin}, issn = {1611-0854}, year = {2012}, language = {de} } @article{SpelthahnSchubertSchoening2012, author = {Spelthahn, Heiko and Schubert, J{\"u}rgen and Sch{\"o}ning, Michael Josef}, title = {D{\"u}nnschichtsensoren f{\"u}r die Schwermetallanalytik : Mikroelektroden auf Chalkogenidglasbasis}, series = {GIT Labor-Fachzeitschrift}, journal = {GIT Labor-Fachzeitschrift}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, pages = {285 -- 287}, year = {2012}, abstract = {Die Detektion von Schadstoffen repr{\"a}sentiert in der Umweltanalytik eine wichtige Aufgabenstellung. Gerade die Abwasser- bzw. Brauchwasseranalytik sowie die Prozesskontrolle haben einen hohen Stellenwert. Siliziumbasierte D{\"u}nnschichtsensoren bieten eine kosteng{\"u}nstige M{\"o}glichkeit, „online"-Messungen bzw. Vor-Ort-Messungen zeitnah durchzuf{\"u}hren. In dieser Arbeit wird ein potentiometrisches Sensorarray auf der Basis von Chalkogenidgl{\"a}sern zur Detektion von Schwermetallen in w{\"a}ssrigen Medien vorgestellt.}, language = {de} } @article{WarmerWagnerSchoeningetal.2015, author = {Warmer, Johannes and Wagner, Patrick and Sch{\"o}ning, Michael Josef and Kaul, Peter}, title = {Detection of triacetone triperoxide using temperature cycled metal-oxide semiconductor gas sensors}, series = {Physica status solidi (a)}, volume = {212}, journal = {Physica status solidi (a)}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201431882}, pages = {1289 -- 1298}, year = {2015}, language = {en} } @article{DelleHuckBaeckeretal.2015, author = {Delle, Lotta E. and Huck, Christina and B{\"a}cker, Matthias and M{\"u}ller, Frank and Grandthyll, Samuel and Jacobs, Karin and Lilischkis, Rainer and Vu, Xuan T. and Sch{\"o}ning, Michael Josef and Wagner, Patrick and Thoelen, Roland and Weil, Maryam and Ingebrandt, Sven}, title = {Impedimetric immunosensor for the detection of histamine based on reduced graphene oxide}, 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.201431863}, pages = {1327 -- 1334}, year = {2015}, language = {en} }