TY - JOUR A1 - Murib, Mohammed S. A1 - Tran, Anh Quang A1 - Ceuninck, Ward de A1 - Schöning, Michael Josef A1 - Nesladek, Milos A1 - Serpengüzel, Ali A1 - Wagner, Patrick T1 - Analysis of an optical biosensor based on elastic light scattering from diamond-, glass-, and sapphire microspheres JF - Physica Status Solidi A N2 - Deoxyribonucleic acid (DNA) and protein recognition are now standard tools in biology. In addition, the special optical properties of microsphere resonators expressed by the high quality factor (Q-factor) of whispering gallery modes (WGMs) or morphology dependent resonances (MDRs) have attracted the attention of the biophotonic community. Microsphere-based biosensors are considered as powerful candidates to achieve label-free recognition of single molecules due to the high sensitivity of their WGMs. When the microsphere surface is modified with biomolecules, the effective refractive index and the effective size of the microsphere change resulting in a resonant wavelength shift. The transverse electric (TE) and the transverse magnetic (TM) elastic light scattering intensity of electromagnetic waves at 600 and 1400 nm are numerically calculated for DNA and unspecific binding of proteins to the microsphere surface. The effect of changing the optical properties was studied for diamond (refractive index 2.34), glass (refractive index 1.50), and sapphire (refractive index 1.75) microspheres with a 50 µm radius. The mode spacing, the linewidth of WGMs, and the shift of resonant wavelength due to the change in radius and refractive index, were analyzed by numerical simulations. Preliminary results of unspecific binding of biomolecules are presented. The calculated shift in WGMs can be used for biomolecules detection. Y1 - 2012 U6 - https://doi.org/10.1002/pssa.201100795 SN - 1862-6319 N1 - Special Issue: "Fundamentals and Applications of Diamond" VL - 209 IS - 9 SP - 1804 EP - 1810 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Yoshinobu, Tatsuo A1 - Miyamoto, Ko-Ichiro A1 - Wagner, Torsten A1 - Schöning, Michael Josef ED - Yamaguchi, Takami T1 - Miniaturized and high-speed chemical imaging systems T2 - Nano-Biomedical Engineering 2012. Proceedings of the Tohoku University Global Centre of Excellence Programme, Sakura Hall, Tohoku University, Sendai Japan, 5 – 6 March 2012 Y1 - 2012 U6 - https://doi.org/10.1142/9781848169067_0045 SP - 386 EP - 395 PB - World Scientific CY - Singapur ER - TY - JOUR A1 - Grinsven, Bart van A1 - Bon, Natalie vanden A1 - Strauven, Hannelore A1 - Grieten, Lars A1 - Murib, Mohammed A1 - Jiménez Monroy, Kathia L. A1 - Janssens, Stoffel D. A1 - Haenen, Ken A1 - Schöning, Michael Josef A1 - Vermeeren, Veronique A1 - Ameloot, Marcel A1 - Michiels, Luc A1 - Thoelen, Ronald A1 - Ceuninck, Ward de A1 - Wagner, Patrick T1 - Heat-Transfer Resistance at Solid-Liquid Interfaces: A Tool for The Detection of Single Nucleotide Polymorphisms in DNA. JF - ACS Nano N2 - In this article, we report on the heat-transfer resistance at interfaces as a novel, denaturation-based method to detect single-nucleotide polymorphisms in DNA. We observed that a molecular brush of double-stranded DNA grafted onto synthetic diamond surfaces does not notably affect the heat-transfer resistance at the solid-to-liquid interface. In contrast to this, molecular brushes of single-stranded DNA cause, surprisingly, a substantially higher heat-transfer resistance and behave like a thermally insulating layer. This effect can be utilized to identify ds-DNA melting temperatures via the switching from low- to high heat-transfer resistance. The melting temperatures identified with this method for different DNA duplexes (29 base pairs without and with built-in mutations) correlate nicely with data calculated by modeling. The method is fast, label-free (without the need for fluorescent or radioactive markers), allows for repetitive measurements, and can also be extended toward array formats. Reference measurements by confocal fluorescence microscopy and impedance spectroscopy confirm that the switching of heat-transfer resistance upon denaturation is indeed related to the thermal on-chip denaturation of DNA. Y1 - 2012 U6 - https://doi.org/10.1021/nn300147e SN - 1936-086X VL - 6 IS - 3 SP - 2712 EP - 2721 PB - ACS Publications CY - Washington, DC ER - TY - CHAP A1 - Schusser, Sebastian A1 - Vaeßen, Christiane A1 - Schöning, Michael Josef T1 - 5. Graduiertentagung der FH Aachen 15. November 2012 T1 - 5th Graduate Symposium FH Aachen - University of Applied Sciences November 15th, 2012 N2 - Tagungsband der 5. Graduiertentagung der FH Aachen am 15. November 2012 N2 - Proceedings from the 5th Graduate Symposium, FH Aachen, Germany, November 15th, 2012 T3 - Graduiertentagung / FH Aachen - 5 KW - Graduiertentagung Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-50425 ER - TY - JOUR A1 - Spelthahn, Heiko A1 - Kirsanov, Dmitry A1 - Legin, Andrey A1 - Osterrath, Thomas A1 - Schubert, Jürgen A1 - Zander, Willi A1 - Schöning, Michael Josef T1 - Development of a thin-film sensor array for analytical monitoring of heavy metals in aqueous solutions JF - Physica Status Solidi (a) N2 - In industrial processes there is a variety of heavy metals (e.g., copper, zinc, cadmium, and lead) in use for wires, coatings, paints, alloys, batteries, etc. Since the application of these transition metals for industry is inevitable, it is a vital task to develop proper analytical techniques for their monitoring at low activity levels, especially because most of these elements are acutely toxic for biological organisms. The determination of ions in solution by means of a simple and inexpensive sensor array is, therefore, a promising task. In this work, a sensor array with heavy metal-sensitive chalcogenide glass membranes for the simultaneous detection of the four ions Ag⁺, Cu2⁺, Cd2⁺, and Pb2⁺ in solution is realized. The results of the physical characterization by means of microscopy, profilometry, Rutherford backscattering spectroscopy (RBS), and scanning electron microscopy (SEM) as well as the electrochemical characterization by means of potentiometric measurements are presented. Additionally, the possibility to expand the sensor array by polymeric sensor membranes is discussed. Y1 - 2012 SN - 1862-6319 U6 - https://doi.org/10.1002/pssa.201100733 VL - 209 IS - 5 SP - 885 EP - 891 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Spelthahn, Heiko A1 - Schubert, Jürgen A1 - Schöning, Michael Josef T1 - Dünnschichtsensoren für die Schwermetallanalytik JF - GIT : Labor-Fachzeitschrift N2 - Die Detektion von Schadstoffen repräsentiert in der Umweltanalytik eine wichtige Aufgabenstellung. Gerade die Abwasser- bzw. Brauchwasseranalytik sowie die Prozesskontrolle haben einen hohen Stellenwert. Siliziumbasierte Dünnschichtsensoren bieten eine kostengünstige Möglichkeit, „online“-Messungen bzw. Vor-Ort-Messungen zeitnah durchzuführen. In dieser Arbeit wird ein potentiometrisches Sensorarray auf der Basis von Chalkogenidgläsern zur Detektion von Schwermetallen in wässrigen Medien vorgestellt. Y1 - 2012 SN - 0016-3538 VL - 56 IS - 4 SP - 285 EP - 287 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Werner, Frederik A1 - Groebel, Simone A1 - Krumbe, Christoph A1 - Wagner, Torsten A1 - Selmer, Thorsten A1 - Yoshinobu, Tatsuo A1 - Baumann, Marcus A1 - Schöning, Michael Josef T1 - Nutrient concentration-sensitive microorganism-based biosensor JF - Physica Status Solidi (a) Y1 - 2012 U6 - https://doi.org/10.1002/pssa.201100801 SN - 1862-6319 VL - 209 IS - 5 SP - 900 EP - 904 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Kirchner, Patrick A1 - Reisert, Steffen A1 - Pütz, Patrick A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Characterisation of polymeric materials as passivation layer for calorimetric H2O2 gas sensors JF - Physica Status Solidi (a) N2 - 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. Y1 - 2012 U6 - https://doi.org/10.1002/pssa.201100773 SN - 1862-6319 VL - 209 IS - 5 SP - 859 EP - 863 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Bohrn, Ulrich A1 - Mucha, Andreas A1 - Werner, Frederik A1 - Stütz, Evamaria A1 - Bäcker, Matthias A1 - Krumbe, Christoph A1 - Schienle, Meinrad A1 - Fleischer, Maximilian A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Detection of toxic chromium species in water using cellbased sensor systems Y1 - 2012 SN - 978-3-9813484-2-2 U6 - https://doi.org/10.5162/IMCS2012/P2.1.14 SP - 1364 EP - 1367 ER - TY - CHAP A1 - Bohrn, Ulrich A1 - Stütz, Evamaria A1 - Fleischer, Maximilian A1 - Schöning, Michael Josef A1 - Wagner, Patrick T1 - Living cell-based gas sensor system for the detection of acetone in air Y1 - 2012 SN - 978-3-9813484-2-2 U6 - https://doi.org/10.5162/IMCS2012/3.2.3 SP - 269 EP - 272 ER -