@article{MiyamotoIchimuraWagneretal.2013, author = {Miyamoto, Ko-ichiro and Ichimura, Hiroki and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Chemical imaging of the concentration profile of ion diffusion in a microfluidic channel}, series = {Sensors and actuators. B: Chemical}, volume = {189}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2013.04.057}, pages = {240 -- 245}, year = {2013}, abstract = {The chemical imaging sensor is a device to visualize the spatial distribution of chemical species based on the principle of LAPS (light-addressable potentiometric sensor), which is a field-effect chemical sensor based on semiconductor. In this study, the chemical imaging sensor has been applied to investigate the ion profile of laminar flows in a microfluidic channel. The chemical images (pH maps) were collected in a Y-shaped microfluidic channel while injecting HCl and NaCl solutions into two branches. From the chemical images, it was clearly observed that the injected solutions formed laminar flows in the channel. In addition, ion diffusion across the laminar flows was observed, and the diffusion coefficient could be derived by fitting the pH profiles to the Fick's equation.}, language = {en} } @article{BohrnMuchaWerneretal.2013, author = {Bohrn, Ulrich and Mucha, Andreas and Werner, Frederik and Trattner, Barbara and B{\"a}cker, Matthias and Krumbe, Christoph and Schienle, Meinrad and St{\"u}tz, Evamaria and Schmitt-Landsiedel, Doris and Fleischer, Maximilian and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {A critical comparison of cell-based sensor systems for the detection of Cr (VI) in aquatic environment}, series = {Sensors and actuators. B: Chemical}, volume = {Vol. 182}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, pages = {58 -- 65}, year = {2013}, language = {en} } @article{WernerTakenagaTakietal.2013, author = {Werner, Frederik and Takenaga, Shoko and Taki, Hidenori and Sawada, Kazuaki and Sch{\"o}ning, Michael Josef}, title = {Comparison of label-free ACh-imaging sensors based on CCD and LAPS}, series = {Sensors and Actuators B: Chemical (2012)}, volume = {177}, journal = {Sensors and Actuators B: Chemical (2012)}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0925-4005}, pages = {745 -- 752}, year = {2013}, abstract = {Semiconductor-based chemical imaging sensors, like the light-addressable potentiometric sensor (LAPS) or the pH-imaging sensor based on a charge-coupled device (CCD), are becoming a powerful tool for label-free imaging of biological phenomena. We have proposed a polyion-based enzymatic membrane to develop an acetylcholine (ACh) imaging sensor for neural cell-activity observations. In this study, a CCD-type ACh-imaging sensor and a LAPS-type ACh-imaging sensor were fabricated and the prospect of both sensors was clarified by making a comparison of their basic characteristics.}, language = {en} } @article{KirchnerOberlaenderSucoetal.2013, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Suco, Henri-Pierre and Rysstad, Gunnar and Sch{\"o}ning, Michael Josef}, title = {Monitoring the microbicidal effectiveness of gaseous hydrogen peroxide in sterilisation processes by means of a calorimetric gas sensor}, series = {Food control}, volume = {31}, journal = {Food control}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0956-7135}, doi = {10.1016/j.foodcont.2012.11.048}, pages = {530 -- 538}, year = {2013}, abstract = {In the present work, a novel method for monitoring sterilisation processes with gaseous H2O2 in combination with heat activation by means of a specially designed calorimetric gas sensor was evaluated. Therefore, the sterilisation process was extensively studied by using test specimens inoculated with Bacillus atrophaeus spores in order to identify the most influencing process factors on its microbicidal effectiveness. Besides the contact time of the test specimens with gaseous H2O2 varied between 0.2 and 0.5 s, the present H2O2 concentration in a range from 0 to 8\% v/v (volume percent) had a strong influence on the microbicidal effectiveness, whereas the change of the vaporiser temperature, gas flow and humidity were almost negligible. Furthermore, a calorimetric H2O2 gas sensor was characterised in the sterilisation process with gaseous H2O2 in a wide range of parameter settings, wherein the measurement signal has shown a linear response against the H2O2 concentration with a sensitivity of 4.75 °C/(\% v/v). In a final step, a correlation model by matching the measurement signal of the gas sensor with the microbial inactivation kinetics was established that demonstrates its suitability as an efficient method for validating the microbicidal effectiveness of sterilisation processes with gaseous H2O2.}, language = {en} } @article{WernerWagnerYoshinobuetal.2013, author = {Werner, Frederik and Wagner, Torsten and Yoshinobu, Tatsuo and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Frequency behaviour of light-addressable potentiometric sensors}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X ; 0031-8965}, doi = {10.1002/pssa.201200929}, pages = {884 -- 891}, year = {2013}, abstract = {Light-addressable potentiometric sensors (LAPS) are semiconductor-based potentiometric sensors, with the advantage to detect the concentration of a chemical species in a liquid solution above the sensor surface in a spatially resolved manner. The addressing is achieved by a modulated and focused light source illuminating the semiconductor and generating a concentration-depending photocurrent. This work introduces a LAPS set-up that is able to monitor the electrical impedance in addition to the photocurrent. The impedance spectra of a LAPS structure, with and without illumination, as well as the frequency behaviour of the LAPS measurement are investigated. The measurements are supported by electrical equivalent circuits to explain the impedance and the LAPS-frequency behaviour. The work investigates the influence of different parameters on the frequency behaviour of the LAPS. Furthermore, the phase shift of the photocurrent, the influence of the surface potential as well as the changes of the sensor impedance will be discussed.}, 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, M. 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{SchiffelsPinkenburgScheldenetal.2013, author = {Schiffels, Johannes and Pinkenburg, Olaf and Schelden, Maximilian and Aboulnaga, El-Hussiny A. A. and Baumann, Marcus and Selmer, Thorsten}, title = {An innovative cloning platform enables large-scale production and maturation of an oxygen-tolerant [NiFe]-hydrogenase from cupriavidus necator in Escherichia coli}, series = {PLOS one. 2013}, journal = {PLOS one. 2013}, publisher = {Public Library of Science}, address = {San Francisco, California}, issn = {1932-6203}, doi = {10.1371/journal.pone.0068812}, year = {2013}, 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{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} } @misc{IngebrandtWagnerSchoening2013, author = {Ingebrandt, Sven and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Engineering of functional interfaces / guest eds. Sven Ingebrandt ; Patrick Wagner ; Michael J. Sch{\"o}ning}, series = {Physica Status Solidi (A)}, volume = {Vol. 210}, journal = {Physica Status Solidi (A)}, number = {Iss. 5}, issn = {1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, pages = {845}, year = {2013}, language = {en} } @misc{AbdelghaniMenaaObareetal.2013, author = {Abdelghani, Adnane and Menaa, Bouzid and Obare, Sherine O. and Sch{\"o}ning, Michael Josef}, title = {Special issue on nanoscale science and technology / guest eds.: Adnane Abdelghani, Bouzid Menaa, Sherine O. Obare, Michael J. Sch{\"o}ning}, series = {International journal of nanotechnology}, volume = {Vol. 10}, journal = {International journal of nanotechnology}, number = {No. 5-7}, issn = {1741-8151 (E-Journal), 1475-7435 (Print)}, pages = {373 -- 619}, 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} } @inproceedings{TakenagaHerreraWerneretal.2013, author = {Takenaga, Shoko and Herrera, Cony F. and Werner, Frederik and Biselli, Manfred and Schnitzler, Thomas and Sch{\"o}ning, Michael Josef and {\"O}hlschl{\"a}ger, Peter and Wagner, Torsten}, title = {Detection of the metabolic activity of cells by differential measurements based on a single light-addressable potentiometric sensor chip}, series = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, booktitle = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, organization = {Dresdner Sensor-Symposium <11, 2013>}, isbn = {978-3-9813484-5-3}, pages = {63 -- 67}, year = {2013}, language = {en} } @inproceedings{OberlaenderReisertKirchneretal.2013, author = {Oberl{\"a}nder, Jan and Reisert, Steffen and Kirchner, Patrick and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Kalorimetrische Gassensoren zur H2O2-Detektion in aseptischen Sterilisationsprozessen}, series = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, booktitle = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, organization = {Dresdner Sensor-Symposium <11, 2013>}, isbn = {978-3-9813484-5-3}, pages = {234 -- 238}, year = {2013}, language = {de} } @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} } @inproceedings{KreyerStollenwerkSchoening2013, author = {Kreyer, J{\"o}rg and Stollenwerk, Dominik and Sch{\"o}ning, Michael Josef}, title = {Tagung des Forschernachwuchses der FH Aachen 20. November 2013 / ed.: J. Kreyer, D. Stollenwerk, M. J. Sch{\"o}ning}, publisher = {FH Aachen}, address = {Aachen}, pages = {64 S.}, year = {2013}, language = {de} } @article{RachingerBauchStrittmatteretal.2013, author = {Rachinger, Michael and Bauch, Melanie and Strittmatter, Axel and Bongaerts, Johannes and Evers, Stefan and Maurer, Karl-Heinz and Daniel, Rolf and Liebl, Wolfgang and Liesegang, Heiko and Ehrenreich, Armin}, title = {Size unlimited markerless deletions by a transconjugative plasmid-system in Bacillus licheniformis}, series = {Journal of biotechnology}, volume = {Vol. 164}, journal = {Journal of biotechnology}, number = {Iss. 4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4863 (E-Journal); 0168-1656 (Print)}, pages = {365 -- 369}, year = {2013}, language = {en} } @article{WilmingBegemannKuhneetal.2013, author = {Wilming, Anja and Begemann, Jens and Kuhne, Stefan and Regestein, Lars and Bongaerts, Johannes and Evers, Stefan and Maurer, Karl-Heinz and B{\"u}chs, Jochen}, title = {Metabolic studies of γ-polyglutamic acid production in Bacillus licheniformis by small-scale continuous cultivations}, series = {Biochemical engineering journal}, volume = {Vol. 73}, journal = {Biochemical engineering journal}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-295X (E-Journal); 1369-703X (Print)}, pages = {29 -- 37}, year = {2013}, language = {en} } @article{ScheeleOertelBongaertsetal.2013, author = {Scheele, Sandra and Oertel, Dan and Bongaerts, Johannes and Evers, Stefan and Hellmuth, Hendrik and Maurer, Karl-Heinz and Bott, Michael and Freudl, Roland}, title = {Secretory production of an FAD cofactor-containing cytosolic enzyme (sorbitol-xylitol oxidase from Streptomyces coelicolor) using the twin-arginine translocation (Tat) pathway of Corynebacterium glutamicum}, series = {Microbial biotechnology}, journal = {Microbial biotechnology}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1751-7915}, pages = {202 -- 206}, year = {2013}, language = {en} } @article{VoigtSchroeterJuergenetal.2013, author = {Voigt, Birgit and Schroeter, Rebecca and J{\"u}rgen, Britta and Albrecht, Dirk and Evers, Stefan and Bongaerts, Johannes and Maurer, Karl-Heinz and Schweder, Thomas and Hecker, Michael}, title = {The response of Bacillus licheniformis to heat and ethanol stress and the role of the SigB regulon}, series = {Proteomics}, volume = {Vol. 13}, journal = {Proteomics}, number = {Iss. 14}, publisher = {Wiley}, address = {Weinheim}, issn = {1615-9861 (E-Journal); 1615-9853 (Print)}, pages = {2140 -- 2146}, year = {2013}, language = {en} } @article{WiegandDietrichHerteletal.2013, author = {Wiegand, Sandra and Dietrich, Sascha and Hertel, Robert and Bongaerts, Johannes and Evers, Stefan and Volland, Sonja and Daniel, Rolf and Liesegang, Heiko}, title = {RNA-Seq of Bacillus licheniformis: active regulatory RNA features expressed within a productive fermentation}, series = {BMC genomics}, volume = {Vol. 14}, journal = {BMC genomics}, publisher = {BioMed Central}, address = {London}, issn = {1471-2164}, pages = {667}, year = {2013}, language = {en} } @inproceedings{WuPoghossianWerneretal.2013, author = {Wu, Chunsheng and Poghossian, Arshak and Werner, Frederik and Bronder, Thomas and B{\"a}cker, Matthias and Wang, Ping and Sch{\"o}ning, Michael Josef}, title = {An application of a scanning light-addressable potentiometric sensor for label-free DNA detection}, series = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, booktitle = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, organization = {Dresdner Sensor-Symposium <11, 2013>}, isbn = {978-3-9813484-5-3}, pages = {164 -- 168}, year = {2013}, language = {en} } @article{HuckSchiffelsHerreraetal.2013, author = {Huck, Christina and Schiffels, Johannes and Herrera, Cony N. and Schelden, Maximilian and Selmer, Thorsten and Poghossian, Arshak and Baumann, Marcus and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Metabolic responses of Escherichia coli upon glucose pulses captured by a capacitive field-effect sensor}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0031-8965}, doi = {10.1002/pssa.201200900}, pages = {926 -- 931}, year = {2013}, abstract = {Living cells are complex biological systems transforming metabolites taken up from the surrounding medium. Monitoring the responses of such cells to certain substrate concentrations is a challenging task and offers possibilities to gain insight into the vitality of a community influenced by the growth environment. Cell-based sensors represent a promising platform for monitoring the metabolic activity and thus, the "welfare" of relevant organisms. In the present study, metabolic responses of the model bacterium Escherichia coli in suspension, layered onto a capacitive field-effect structure, were examined to pulses of glucose in the concentration range between 0.05 and 2 mM. It was found that acidification of the surrounding medium takes place immediately after glucose addition and follows Michaelis-Menten kinetic behavior as a function of the glucose concentration. In future, the presented setup can, therefore, be used to study substrate specificities on the enzymatic level and may as well be used to perform investigations of more complex metabolic responses. Conclusions and perspectives highlighting this system are discussed.}, language = {en} } @article{SchusserMenzelBaeckeretal.2013, author = {Schusser, Sebastian and Menzel, S. and B{\"a}cker, Matthias and Leinhos, Marcel and Poghossian, Arshak and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Degradation of thin poly(lactic acid) films: characterization by capacitance-voltage, atomic force microscopy, scanning electron microscopy and contact-angle measurements}, series = {Electrochimica Acta}, volume = {Vol. 113}, journal = {Electrochimica Acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3859 (E-Journal); 0013-4686 (Print)}, pages = {779 -- 784}, year = {2013}, language = {en} } @inproceedings{HuckPoghossianBaeckeretal.2013, author = {Huck, Christina and Poghossian, Arshak and B{\"a}cker, Matthias and Zander, W. and Schubert, J. and Sukoyan, L. H. and Begoyan, V. and Buniatyan, V. V. and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Chemische Sensoren mit Bariumstrontiumtitanat als funktionelle Schicht zur Multiparameterdetektion}, series = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, booktitle = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, organization = {Dresdner Sensor-Symposium <11, 2013>}, isbn = {978-3-9813484-5-3}, pages = {368 -- 372}, year = {2013}, language = {de} } @inproceedings{SchusserBaeckerLeinhosetal.2013, author = {Schusser, Sebastian and B{\"a}cker, Matthias and Leinhos, Marcel and Krischer, M. and Wenzel, L. and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Sensorkonzept zur in vitro Echtzeitmessung des Degradationsverhaltens von biodegradierbaren Biopolymeren}, series = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, booktitle = {11. Dresdner Sensor-Symposium : 9.-11.12.2013}, organization = {Dresdner Sensor-Symposium <11, 2013>}, isbn = {978-3-9813484-5-3}, pages = {174 -- 177}, year = {2013}, language = {de} } @article{BuniatyanHuckPoghossianetal.2013, author = {Buniatyan, V. and Huck, Christina and Poghossian, Arshak and Aroutiounian, V. M. and Sch{\"o}ning, Michael Josef}, title = {BaxSr1-x TiO3/pc-Si heterojunction}, series = {Armenian journal of physics}, volume = {6}, journal = {Armenian journal of physics}, number = {4}, publisher = {National Academy of Sciences of Armenia}, address = {Yerevan}, issn = {1829-1171}, pages = {177 -- 187}, year = {2013}, language = {en} } @article{SchusserLeinhosBaeckeretal.2013, author = {Schusser, Sebastian and Leinhos, Marcel and B{\"a}cker, Matthias and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Impedance spectroscopy: A tool for real-time in situ monitoring of the degradation of biopolymers}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-396X ; 0031-8965}, doi = {10.1002/pssa.201200941}, pages = {905 -- 910}, year = {2013}, abstract = {Investigation of the degradation kinetics of biodegradable polymers is essential for the development of implantable biomedical devices with predicted biodegradability. In this work, an impedimetric sensor has been applied for real-time and in situ monitoring of degradation processes of biopolymers. The sensor consists of two platinum thin-film electrodes covered by a polymer film to be studied. The benchmark biomedical polymer poly(D,L-lactic acid) (PDLLA) was used as a model system. PDLLA films were deposited on the sensor structure from a polymer solution by using the spin-coating method. The degradation kinetics of PDLLA films have been studied in alkaline solutions of pH 9 and 12 by means of an impedance spectroscopy (IS) method. Any changes in a polymer capacitance/resistance induced by water uptake and/or polymer degradation will modulate the global impedance of the polymer-covered sensor that can be used as an indicator of the polymer degradation. The degradation rate can be evaluated from the time-dependent impedance spectra. As expected, a faster degradation has been observed for PDLLA films exposed to pH 12 solution.}, language = {en} } @article{AbulnagaPinkenburgSchiffelsetal.2013, author = {Abulnaga, El-Hussiny and Pinkenburg, Olaf and Schiffels, Johannes and E-Refai, Ahmed and Buckel, Wolfgang and Selmer, Thorsten}, title = {Effect of an Oxygen-Tolerant Bifurcating Butyryl Coenzyme A Dehydrogenase/Electron-Transferring Flavoprotein Complex from Clostridium difficile on Butyrate Production in Escherichia coli}, series = {Journal of bacteriology}, volume = {195}, journal = {Journal of bacteriology}, number = {16}, issn = {1098-5530 [E-Journal]}, pages = {3704 -- 3713}, year = {2013}, language = {en} } @article{PoghossianWeilCherstvyetal.2013, author = {Poghossian, Arshak and Weil, M. and Cherstvy, A. G. and Sch{\"o}ning, Michael Josef}, title = {Electrical monitoring of polyelectrolyte multilayer formation by means of capacitive field-effect devices}, series = {Analytical and bioanalytical chemistry}, volume = {405}, journal = {Analytical and bioanalytical chemistry}, number = {20}, publisher = {Springer}, address = {Berlin}, issn = {1432-1130 ; 1618-2642}, doi = {10.1007/s00216-013-6951-9}, pages = {6425 -- 6436}, year = {2013}, abstract = {The semiconductor field-effect platform represents a powerful tool for detecting the adsorption and binding of charged macromolecules with direct electrical readout. In this work, a capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensor consisting of an Al-p-Si-SiO2 structure has been applied for real-time in situ electrical monitoring of the layer-by-layer formation of polyelectrolyte (PE) multilayers (PEM). The PEMs were deposited directly onto the SiO2 surface without any precursor layer or drying procedures. Anionic poly(sodium 4-styrene sulfonate) and cationic weak polyelectrolyte poly(allylamine hydrochloride) have been chosen as a model system. The effect of the ionic strength of the solution, polyelectrolyte concentration, number and polarity of the PE layers on the characteristics of the PEM-modified EIS sensors have been studied by means of capacitance-voltage and constant-capacitance methods. In addition, the thickness, surface morphology, roughness and wettabilityof the PE mono- and multilayers have been characterised by ellipsometry, atomic force microscopy and water contact-angle methods, respectively. To explain potential oscillations on the gate surface and signal behaviour of the capacitive field-effect EIS sensor modified with a PEM, a simplified electrostatic model that takes into account the reduced electrostatic screening of PE charges by mobile ions within the PEM has been proposed and discussed.}, language = {en} } @article{KramerHalamkovaPoghossianetal.2013, author = {Kramer, Friederike and Halamkova, Lenka and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Katz, Evgeny and Halamek, Jan}, title = {Biocatalytic analysis of biomarkers for forensic identification of ethnicity between Caucasian and African American}, series = {The analyst. August 2013}, volume = {Vol. 138}, journal = {The analyst. August 2013}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1364-5528 (E-Journal); 0003-2654 (Print)}, pages = {6251 -- 6257}, year = {2013}, language = {en} } @article{BaeckerRakowskiPoghossianetal.2013, author = {B{\"a}cker, Matthias and Rakowski, D. and Poghossian, Arshak and Biselli, Manfred and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Chip-based amperometric enzyme sensor system for monitoring of bioprocesses by flow-injection analysis}, series = {Journal of Biotechnology}, volume = {163}, journal = {Journal of Biotechnology}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-1656}, doi = {10.1016/j.jbiotec.2012.03.014}, pages = {371 -- 376}, year = {2013}, abstract = {A microfluidic chip integrating amperometric enzyme sensors for the detection of glucose, glutamate and glutamine in cell-culture fermentation processes has been developed. The enzymes glucose oxidase, glutamate oxidase and glutaminase were immobilized by means of cross-linking with glutaraldehyde on platinum thin-film electrodes integrated within a microfluidic channel. The biosensor chip was coupled to a flow-injection analysis system for electrochemical characterization of the sensors. The sensors have been characterized in terms of sensitivity, linear working range and detection limit. The sensitivity evaluated from the respective peak areas was 1.47, 3.68 and 0.28 μAs/mM for the glucose, glutamate and glutamine sensor, respectively. The calibration curves were linear up to a concentration of 20 mM glucose and glutamine and up to 10 mM for glutamate. The lower detection limit amounted to be 0.05 mM for the glucose and glutamate sensor, respectively, and 0.1 mM for the glutamine sensor. Experiments in cell-culture medium have demonstrated a good correlation between the glutamate, glutamine and glucose concentrations measured with the chip-based biosensors in a differential-mode and the commercially available instrumentation. The obtained results demonstrate the feasibility of the realized microfluidic biosensor chip for monitoring of bioprocesses.}, language = {en} } @article{BaeckerSchusserPoghossianetal.2013, author = {B{\"a}cker, Matthias and Schusser, Sebastian and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Degradationsverhalten bioabbaubarer Polymere : siliziumbasierte Sensorik zur {\"U}berwachung}, series = {GIT Labor-Fachzeitschrift}, journal = {GIT Labor-Fachzeitschrift}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0016-3538}, pages = {32 -- 33}, year = {2013}, language = {de} } @article{BuniatyanHuckPoghossianetal.2013, author = {Buniatyan, V. and Huck, Christina and Poghossian, Arshak and Aroutiounian, V. M. and Sch{\"o}ning, Michael Josef}, title = {BaxSr1-x TiO3/pc-Si heterojunction capacitance}, series = {Armenian journal of physics}, volume = {6}, journal = {Armenian journal of physics}, number = {4}, publisher = {National Academy of Sciences of Armenia}, address = {Yerevan}, issn = {1829-1171}, pages = {188 -- 197}, 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{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} } @phdthesis{Werner2014, author = {Werner, Frederik}, title = {Development of light-addressable potentiometric sensor systems and their applications in biotechnological environments}, pages = {XI, 149 S.}, year = {2014}, 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{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} } @incollection{KirchnerReisertSchoening2014, author = {Kirchner, Patrick and Reisert, Steffen and Sch{\"o}ning, Michael Josef}, title = {Calorimetric gas sensors for hydrogen peroxide monitoring in aseptic food processes}, series = {Gas sensing fundamentals. (Springer Series on Chemical Sensors and Biosensors ; 15)}, booktitle = {Gas sensing fundamentals. (Springer Series on Chemical Sensors and Biosensors ; 15)}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-642-54518-4 (Print) ; 978-3-642-54519-1 (Online)}, doi = {10.1007/5346_2013_51}, pages = {279 -- 309}, year = {2014}, abstract = {For the sterilisation of aseptic food packages it is taken advantage of the microbicidal properties of hydrogen peroxide (H2O2). Especially, when applied in vapour phase, it has shown high potential of microbial inactivation. In addition, it offers a high environmental compatibility compared to other chemical sterilisation agents, as it decomposes into oxygen and water, respectively. Due to a lack in sensory detection possibilities, a continuous monitoring of the H2O2 concentration was recently not available. Instead, the sterilisation efficacy is validated using microbiological tests. However, progresses in the development of calorimetric gas sensors during the last 7 years have made it possible to monitor the H2O2 concentration during operation. This chapter deals with the fundamentals of calorimetric gas sensing with special focus on the detection of gaseous hydrogen peroxide. A sensor principle based on a calorimetric differential set-up is described. Special emphasis is given to the sensor design with respect to the operational requirements under field conditions. The state-of-the-art regarding a sensor set-up for the on-line monitoring and secondly, a miniaturised sensor for in-line monitoring are summarised. Furthermore, alternative detection methods and a novel multi-sensor system for the characterisation of aseptic sterilisation processes are described.}, 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{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} }