@article{BronderWuPoghossianetal.2014, author = {Bronder, Thomas and Wu, Chunsheng and Poghossian, Arshak and Werner, Frederik and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Label-free detection of DNA hybridization with light-addressable potentiometric sensors: comparison of various DNA-immobilization strategies}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.647}, pages = {755 -- 758}, year = {2014}, abstract = {Light-addressable potentiometric sensors (LAPS) consisting of a p-Si-SiO2 and p-Si-SiO2-Au structure, respectively, have been tested for a label-free electrical detection of DNA (deoxyribonucleic acid) hybridization. Three different strategies for immobilizing single-stranded probe DNA (ssDNA) molecules on a LAPS surface have been studied and compared: (a) immobilization of thiol-modified ssDNA on the patterned Au surface via gold-thiol bond, (b) covalent immobilization of amino-modified ssDNA onto the SiO2 surface functionalized with 3-aminopropyltriethoxysilane and (c) layer-by-layer adsorption of negatively charged ssDNA on a positively charged weak polyelectrolyte layer of poly(allylamine hydrochloride).}, language = {en} } @article{WuBronderPoghossianetal.2015, author = {Wu, Chunsheng and Bronder, Thomas and Poghossian, Arshak and Werner, Frederik and Sch{\"o}ning, Michael Josef}, title = {Label-free detection of DNA using light-addressable potentiometric sensor modified with a positively charged polyelectrolyte layer}, series = {Nanoscale}, volume = {14}, journal = {Nanoscale}, number = {7}, publisher = {Royal Society of Chemistry (RSC)}, address = {Cambridge}, doi = {10.1039/C4NR07225A}, pages = {6143 -- 6150}, year = {2015}, abstract = {A multi-spot (16 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al-p-Si-SiO2 structure modified with a weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. To achieve a preferentially flat orientation of DNA strands and thus, to reduce the distance between the DNA charge and MLAPS surface, the negatively charged probe single-stranded DNAs (ssDNA) were electrostatically adsorbed onto the positively charged PAH layer using a simple layer-by-layer (LbL) technique. In this way, more DNA charge can be positioned within the Debye length, yielding a higher sensor signal. The surface potential changes in each spot induced due to the surface modification steps (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), non-specific adsorption of mismatched ssDNA) were determined from the shifts of photocurrent-voltage curves along the voltage axis. A high sensor signal of 83 mV was registered after immobilization of probe ssDNA onto the PAH layer. The hybridization signal increases from 5 mV to 32 mV with increasing the concentration of cDNA from 0.1 nM to 5 μM. In contrast, a small signal of 5 mV was recorded in the case of non-specific adsorption of fully mismatched ssDNA (5 μM). The obtained results demonstrate the potential of the MLAPS in combination with the simple and rapid LbL immobilization technique as a promising platform for the future development of multi-spot light-addressable label-free DNA chips with direct electrical readout.}, language = {en} } @article{BronderPoghossianKeusgenetal.2017, author = {Bronder, Thomas and Poghossian, Arshak and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Label-free detection of double-stranded DNA molecules with polyelectrolyte-modified capacitive field-effect sensors}, series = {tm - Technisches Messen}, volume = {84}, journal = {tm - Technisches Messen}, number = {10}, publisher = {De Gruyter}, address = {Oldenbourg}, doi = {10.1515/teme-2017-0015}, pages = {628 -- 634}, year = {2017}, abstract = {In this study, polyelectrolyte-modified field-effect-based electrolyte-insulator-semiconductor (EIS) devices have been used for the label-free electrical detection of double-stranded deoxyribonucleic acid (dsDNA)molecules. The sensor-chip functionalization with a positively charged polyelectrolyte layer provides the possibility of direct adsorptive binding of negatively charged target DNA oligonucleotides onto theSiO2-chip surface.EIS sensors can be utilized as a tool to detect surface-charge changes; the electrostatic adsorption of oligonucleotides onto the polyelectrolyte layer leads to a measureable surface-potential change. Signals of 39mV have been recorded after the incubation with the oligonucleotide solution. Besides the electrochemical experiments, the successful adsorption of dsDNA onto the polyelectrolyte layer has been verified via fluorescence microscopy. The presented results demonstrate that the signal recording of EISchips, which are modified with a polyelectrolyte layer, canbe used as a favorable approach for a fast, cheap and simple detection method for dsDNA.}, language = {en} } @article{IngebrandtHanNakamuraetal.2007, author = {Ingebrandt, S. and Han, Y. and Nakamura, F. and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Offenh{\"a}usser, A.}, title = {Label-free detection of single nucleotide polymorphisms utilizing the differential transfer function of field-effect transistors}, series = {Biosensors and Bioelectronics. 22 (2007), H. 12}, journal = {Biosensors and Bioelectronics. 22 (2007), H. 12}, isbn = {0956-5663}, pages = {2834 -- 2840}, year = {2007}, language = {en} } @article{SchoeningBronderWuetal.2017, author = {Sch{\"o}ning, Michael Josef and Bronder, Thomas and Wu, Chunsheng and Scheja, Sabrina and Jessing, Max and Metzger-Boddien, Christoph and Keusgen, Michael and Poghossian, Arshak}, title = {Label-Free DNA Detection with Capacitive Field-Effect Devices—Challenges and Opportunities}, series = {Proceedings}, volume = {1}, journal = {Proceedings}, number = {8}, publisher = {MDPI}, address = {Basel}, issn = {2504-3900}, doi = {10.3390/proceedings1080719}, pages = {Artikel 719}, year = {2017}, abstract = {Field-effect EIS (electrolyte-insulator-semiconductor) sensors modified with a positively charged weak polyelectrolyte layer have been applied for the electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge. The EIS sensors are able to detect the existence of target DNA amplicons in PCR (polymerase chain reaction) samples and thus, can be used as tool for a quick verification of DNA amplification and the successful PCR process. Due to their miniaturized setup, compatibility with advanced micro- and nanotechnologies, and ability to detect biomolecules by their intrinsic molecular charge, those sensors can serve as possible platform for the development of label-free DNA chips. Possible application fields as well as challenges and limitations will be discussed.}, language = {en} } @article{AbouzarPedrazaSchoeningetal.2010, author = {Abouzar, Maryam H. and Pedraza, A. M. and Sch{\"o}ning, Michael Josef and Poghossian, Arshak}, title = {Label-free DNA hybridization and denaturation detection by means of field-effect nanoplate SOI capacitors functionalized with gold nanoparticles}, series = {Procedia Engineering}, volume = {5}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2010.09.259}, pages = {918 -- 921}, year = {2010}, abstract = {A new approach for a label-free electrical detection of DNA hybridization and denaturation using an array of individually addressable field-effect nanoplate SOI (silicon-on-insulator) capacitors functionalized with gold nanoparticles is presented. By using a constant-capacitance measuring setup in a differential mode, signal changes of ∼110 mV and ∼70 mV have been registered after the DNA hybridization and denaturation events, respectively.}, language = {en} } @article{AbouzarPoghossianCherstvyetal.2012, author = {Abouzar, Maryam H. and Poghossian, Arshak and Cherstvy, Andrey G. and Pedraza, Angela M. and Ingebrandt, Sven and Sch{\"o}ning, Michael Josef}, title = {Label-free electrical detection of DNA by means of field-effect nanoplate capacitors: Experiments and modeling}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100710}, pages = {925 -- 934}, year = {2012}, abstract = {Label-free electrical detection of consecutive deoxyribonucleic acid (DNA) hybridization/denaturation by means of an array of individually addressable field-effect-based nanoplate silicon-on-insulator (SOI) capacitors modified with gold nanoparticles (Au-NP) is investigated. The proposed device detects charge changes on Au-NP/DNA hybrids induced by the hybridization or denaturation event. DNA hybridization was performed in a high ionic-strength solution to provide a high hybridization efficiency. On the other hand, to reduce the screening of the DNA charge by counter ions and to achieve a high sensitivity, the sensor signal induced by the hybridization and denaturation events was measured in a low ionic-strength solution. High sensor signals of about 120, 90, and 80 mV were registered after the DNA hybridization, denaturation, and re-hybridization events, respectively. Fluorescence microscopy has been applied as reference method to verify the DNA immobilization, hybridization, and denaturation processes. An electrostatic charge-plane model for potential changes at the gate surface of a nanoplate field-effect sensor induced by the DNA hybridization has been developed taking into account both the Debye length and the distance of the DNA charge from the gate surface.}, language = {en} } @article{WuBronderPoghossianetal.2014, author = {Wu, Chunsheng and Bronder, Thomas and Poghossian, Arshak and Werner, Frederik and B{\"a}cker, Matthias and Sch{\"o}ning, Michael Josef}, title = {Label-free electrical detection of DNA with a multi-spot LAPS: First step towards light-addressable DNA chips}, 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.201330442}, pages = {1423 -- 1428}, year = {2014}, abstract = {A multi-spot (4 × 4 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al-p-Si-SiO2 structure has been applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. Single-stranded probe ssDNA molecules (20 bases) were covalently immobilized onto the silanized SiO2 gate surface. The unspecific adsorption of mismatch ssDNA on the MLAPS gate surface was blocked by bovine serum albumin molecules. To reduce the screening effect and to achieve a high sensor signal, the measurements were performed in a low ionic-strength solution. The photocurrent-voltage (I-V) curves were simultaneously recorded on all 16 spots after each surface functionalization step. Large shifts of I-V curves of 25 mV were registered after the DNA immobilization and hybridization event. In contrast, a small potential shift (∼5 mV) was observed in case of mismatch ssDNA, revealing good specificity of the sensor. The obtained results demonstrate the potential of the MLAPS as promising transducer platform for the multi-spot label-free electrical detection of DNA molecules by their intrinsic molecular charge.}, language = {en} } @article{PoghossianSchoening2014, author = {Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Label-free sensing of biomolecules with field-effect devices for clinical applications}, series = {Electroanalysis}, volume = {26}, journal = {Electroanalysis}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-4109 (E-Journal); 1040-0397 (Print)}, doi = {10.1002/elan.201400073}, pages = {1197 -- 1213}, year = {2014}, abstract = {Among the variety of transducer concepts proposed for label-free detection of biomolecules, the semiconductor field-effect device (FED) is one of the most attractive platforms. As medical techniques continue to progress towards diagnostic and therapies based on biomarkers, the ability of FEDs for a label-free, fast and real-time detection of multiple pathogenic and physiologically relevant molecules with high specificity and sensitivity offers very promising prospects for their application in point-of-care and personalized medicine for an early diagnosis and treatment of diseases. The presented paper reviews recent advances and current trends in research and development of different FEDs for label-free, direct electrical detection of charged biomolecules by their intrinsic molecular charge. The authors are mainly focusing on the detection of the DNA hybridization event, antibody-antigen affinity reaction as well as clinically relevant biomolecules such as cardiac and cancer biomarkers.}, language = {en} } @article{ZischankHeidlerWiesingeretal.2004, author = {Zischank, Wolfgang J. and Heidler, Fridolin and Wiesinger, J. and Metwally, I. and Kern, Alexander and Seevers, M.}, title = {Laboratory simulation of direct lightning strokes to a modeled building : measurement of magnetic fields and included voltages}, series = {Journal of electrostatics. 60 (2004), H. 2 - 4}, journal = {Journal of electrostatics. 60 (2004), H. 2 - 4}, isbn = {0304-3886}, pages = {223 -- 232}, year = {2004}, language = {en} } @article{SchwarzerWernerHartz2004, author = {Schwarzer, Klemens and Werner, M. and Hartz, T.}, title = {Lacasa - an instrument for the energy analysis and optimisation of buildings including technical equipment}, series = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 2}, journal = {Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft f{\"u}r Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 2}, publisher = {PSE}, address = {Freiburg [Breisgau]}, isbn = {3-9809656-2-7}, pages = {2-489-2-494}, year = {2004}, language = {en} } @article{Mertens1992, author = {Mertens, Josef}, title = {Laminar flow for supersonic transports}, series = {Proceedings : March 16 - 18, 1992, Congress Centrum, Hamburg, Federal Republic of Germany / organized jointly by: Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt e.V. ... [Programme committee J. Szodruch ...]}, journal = {Proceedings : March 16 - 18, 1992, Congress Centrum, Hamburg, Federal Republic of Germany / organized jointly by: Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt e.V. ... [Programme committee J. Szodruch ...]}, publisher = {DGLR}, address = {Bonn}, isbn = {3-922010-73-3}, pages = {319 -- 323}, year = {1992}, language = {en} } @article{WittmannUlamecRichter1999, author = {Wittmann, Klaus and Ulamec, S and Richter, L}, title = {Lander Systems for Planetary Missions}, series = {Laboratory astrophysics and space research / ed. by P. Ehrenfreund}, journal = {Laboratory astrophysics and space research / ed. by P. Ehrenfreund}, publisher = {Kluwer}, address = {Dordrecht [u.a.]}, isbn = {0-7923-5338-2}, pages = {597 -- 621}, year = {1999}, language = {en} } @article{FerreinBeckLakemeyer2009, author = {Ferrein, Alexander and Beck, Daniel and Lakemeyer, Gerhard}, title = {Landmark-Based Representations for Navigating Holonomic Soccer Robots / Beck, Daniel ; Ferrein, Alexander ; Lakemeyer, Gerhard}, series = {RoboCup 2008 : robot soccer world cup XII / Luca Iocchi ... (eds.)}, journal = {RoboCup 2008 : robot soccer world cup XII / Luca Iocchi ... (eds.)}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-642-02921-9}, pages = {25 -- 36}, year = {2009}, language = {en} } @article{DantismRoehlenDahmenetal.2020, author = {Dantism, Shahriar and R{\"o}hlen, Desiree and Dahmen, Markus and Wagner, Torsten and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {LAPS-based monitoring of metabolic responses of bacterial cultures in a paper fermentation broth}, series = {Sensors and Actuators B: Chemical}, volume = {320}, journal = {Sensors and Actuators B: Chemical}, number = {Art. 128232}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2020.128232}, year = {2020}, abstract = {As an alternative renewable energy source, methane production in biogas plants is gaining more and more attention. Biomass in a bioreactor contains different types of microorganisms, which should be considered in terms of process-stability control. Metabolically inactive microorganisms within the fermentation process can lead to undesirable, time-consuming and cost-intensive interventions. Hence, monitoring of the cellular metabolism of bacterial populations in a fermentation broth is crucial to improve the biogas production, operation efficiency, and sustainability. In this work, the extracellular acidification of bacteria in a paper-fermentation broth is monitored after glucose uptake, utilizing a differential light-addressable potentiometric sensor (LAPS) system. The LAPS system is loaded with three different model microorganisms (Escherichia coli, Corynebacterium glutamicum, and Lactobacillus brevis) and the effect of the fermentation broth at different process stages on the metabolism of these bacteria is studied. In this way, different signal patterns related to the metabolic response of microorganisms can be identified. By means of calibration curves after glucose uptake, the overall extracellular acidification of bacterial populations within the fermentation process can be evaluated.}, language = {en} } @article{RoesnerScheikOlowinskyetal.2011, author = {Roesner, Andreas and Scheik, Sven and Olowinsky, Alexander and Gillner, Arnold and Reisgen, Uwe and Schleser, Markus}, title = {Laser assisted joining of plastic metal hybrids}, series = {Lasers in manufacturing 2011 : proceedings of the sixth International WLT Conference on Lasers in Manufacturing, Munich, May 23 - 26 2011. (Physics procedia ; Vol. 12 (2011), Part B)}, journal = {Lasers in manufacturing 2011 : proceedings of the sixth International WLT Conference on Lasers in Manufacturing, Munich, May 23 - 26 2011. (Physics procedia ; Vol. 12 (2011), Part B)}, publisher = {Elsevier}, address = {Amsterdam}, organization = {International WLT Conference on Lasers in Manufacturing <6, M{\"u}nchen, 2011>}, issn = {1875-3892 (E-Journal); 1875-3884 (Print)}, pages = {370 -- 377}, year = {2011}, language = {en} } @article{ReisgenOlschokJakobsetal.2012, author = {Reisgen, Uwe and Olschok, Simon and Jakobs, Stefan and Schleser, Markus and Mokrov, Oleg and Rossiter, Eduardo}, title = {Laser beam submerged arc hybrid welding}, series = {Physics procedia}, volume = {39}, journal = {Physics procedia}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1875-3892}, doi = {10.1016/j.phpro.2012.10.016}, pages = {75 -- 83}, year = {2012}, abstract = {The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The high deposition rate of the SA process in combination with the laser beam process offers, providing the appropriate choice of weld preparation, the possibility of welding plates with a thickness larger than 20° mm in a single pass, and also of welding thicker plates with the double-sided single pass technique.}, language = {en} } @article{FerreinStrackLakemeyer2006, author = {Ferrein, Alexander and Strack, Andreas and Lakemeyer, Gerhard}, title = {Laser-Based Localization with Sparse Landmarks / Strack, Andreas ; Ferrein, Alexander ; Lakemeyer, Gerhard}, series = {RoboCup 2005: Robot Soccer World Cup IX}, journal = {RoboCup 2005: Robot Soccer World Cup IX}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-35437-6}, pages = {569 -- 576}, year = {2006}, language = {en} } @article{ErmolenkoYoshinobuMourzinaetal.2004, author = {Ermolenko, Y. E. and Yoshinobu, T. and Mourzina, Y. G. and Vlasov, Y. G. and Sch{\"o}ning, Michael Josef and Iwasaki, H.}, title = {Laserscanned transducer (LSST) as a multisensor system}, series = {Sensors and Actuators B. 103 (2004), H. 1-2}, journal = {Sensors and Actuators B. 103 (2004), H. 1-2}, isbn = {0925-4005}, pages = {457 -- 462}, year = {2004}, language = {en} } @article{Gebhardt2001, author = {Gebhardt, Andreas}, title = {Laserwelding with fillerwire}, series = {LIA handbook of laser material processing / Laser Institute of America}, journal = {LIA handbook of laser material processing / Laser Institute of America}, address = {Orlando, Florida}, isbn = {3-540-41770-2}, year = {2001}, language = {en} }