TY - JOUR A1 - Ermelenko, Y. A1 - Yoshinobu, T. A1 - Mourzina, Y. A1 - Schöning, Michael Josef A1 - Vlasov, Y. A1 - Iwasaki, H. T1 - The hybrid K+/Ca2+ sensor based on laser scanned silicon transducer for multi-component analysis JF - Proceedings of ICAS 2001, IUPAC [3rd] International Congress on Analytical Sciences 2001 : August 6 - 10, 2001, Waseda University, Tokyo Y1 - 2002 N1 - International Congress on Analytical Sciences <2001, Tokyo> ; International Union of Pure and Applied Chemistry. Pure and applied chemistry ; 73,10. ; Analytical sciences ; 17.2001, special issue SP - i777 EP - i780 PB - Japan Society for Analytical Chemistry CY - Tokyo ER - TY - JOUR A1 - Ermelenko, Y. A1 - Yoshinobu, T. A1 - Mourzina, Y. A1 - Schöning, Michael Josef A1 - Furuichi, K. A1 - Levichev, S. A1 - Vlasov, Y. A1 - Iwasaki, H. T1 - The double K+/Ca2+ sensor based on laser scanned silicon transducer (LSST) for multicomponent analysis JF - Talanta. 59 (2003), H. 4 Y1 - 2003 SN - 0039-9140 SP - 785 EP - 795 ER - TY - JOUR A1 - Ermelenko, Y. A1 - Yoshinobu, T. A1 - Mourzina, Y. A1 - Furuichi, K. A1 - Levichev, S. A1 - Vlasov, Y. A1 - Schöning, Michael Josef A1 - Iwasaki, H. T1 - Lithium sensor based on the laser scanning semiconductor transducer JF - Analytica Chimica Acta. 459 (2002), H. 1 Y1 - 2002 SN - 0378-4304 SP - 1 EP - 9 ER - TY - JOUR A1 - Ermelenko, Y. A1 - Yoshinobu, T. A1 - Mourzina, Y. A1 - Furuichi, K. A1 - Iwasaki, H. A1 - Vlasov, Y. A1 - Schöning, Michael Josef T1 - Technology of photocurable polymeric membranes for integrated LAPS JF - Proceedings of the 5th East Asian Conference on Chemical Sensors; the 33rd Chemical Sensor Symposium : December 4 - 7, 2001, Huis Ten Bosch, Sasebo-shi, Nagasaki, Japan / Japan Association of Chemical Sensors; the Electrochemical Society of Japan Y1 - 2001 N1 - Chemical sensors; 17.2001 Suppl. B; East Asian Conference on Chemical Sensors ; (5, 2001; Nagasaki) SP - 66 EP - 68 PB - Japan Association of Chemical Sensors CY - Kasuga, Fukuoka-ken ER - TY - JOUR A1 - Ermelenko, Y. A1 - Yoshinobu, T A1 - Mourzina, Y. A1 - Levichev, S. A1 - Furuichi, K. A1 - Vlasov, Y. A1 - Schöning, Michael Josef A1 - Iwasaki, H. T1 - Photocurable membranes for ion-selective light-addressable potentiometric sensors JF - Sensors and Actuators B. 85 (2002), H. 1-2 Y1 - 2002 SN - 0925-4005 SP - 79 EP - 85 ER - TY - JOUR A1 - Engelmann, Ulrich M. A1 - Simsek, Beril A1 - Shalaby, Ahmed A1 - Krause, Hans-Joachim T1 - Key contributors to signal generation in frequency mixing magnetic detection (FMMD): an in silico study JF - Sensors N2 - Frequency mixing magnetic detection (FMMD) is a sensitive and selective technique to detect magnetic nanoparticles (MNPs) serving as probes for binding biological targets. Its principle relies on the nonlinear magnetic relaxation dynamics of a particle ensemble interacting with a dual frequency external magnetic field. In order to increase its sensitivity, lower its limit of detection and overall improve its applicability in biosensing, matching combinations of external field parameters and internal particle properties are being sought to advance FMMD. In this study, we systematically probe the aforementioned interaction with coupled Néel–Brownian dynamic relaxation simulations to examine how key MNP properties as well as applied field parameters affect the frequency mixing signal generation. It is found that the core size of MNPs dominates their nonlinear magnetic response, with the strongest contributions from the largest particles. The drive field amplitude dominates the shape of the field-dependent response, whereas effective anisotropy and hydrodynamic size of the particles only weakly influence the signal generation in FMMD. For tailoring the MNP properties and parameters of the setup towards optimal FMMD signal generation, our findings suggest choosing large particles of core sizes dc > 25 nm nm with narrow size distributions (σ < 0.1) to minimize the required drive field amplitude. This allows potential improvements of FMMD as a stand-alone application, as well as advances in magnetic particle imaging, hyperthermia and magnetic immunoassays. KW - key performance indicators KW - magnetic biosensing KW - coupled Néel–Brownian relaxation dynamics KW - frequency mixing magnetic detection KW - magnetic relaxation KW - micromagnetic simulation KW - magnetic nanoparticles Y1 - 2024 U6 - http://dx.doi.org/10.3390/s24061945 SN - 1424-8220 N1 - This article belongs to the Special Issue "Advances in Magnetic Sensors and Their Applications" VL - 24 IS - 6 PB - MDPI CY - Basel ER - TY - JOUR A1 - Engelmann, Ulrich M. A1 - Pourshahidi, Mohammad Ali A1 - Shalaby, Ahmed A1 - Krause, Hans-Joachim T1 - Probing particle size dependency of frequency mixing magnetic detection with dynamic relaxation simulation JF - Journal of Magnetism and Magnetic Materials N2 - Biomedical applications of magnetic nanoparticles (MNP) fundamentally rely on the particles’ magnetic relaxation as a response to an alternating magnetic field. The magnetic relaxation complexly depends on the interplay of MNP magnetic and physical properties with the applied field parameters. It is commonly accepted that particle core size is a major contributor to signal generation in all the above applications, however, most MNP samples comprise broad distribution spanning nm and more. Therefore, precise knowledge of the exact contribution of individual core sizes to signal generation is desired for optimal MNP design generally for each application. Specifically, we present a magnetic relaxation simulation-driven analysis of experimental frequency mixing magnetic detection (FMMD) for biosensing to quantify the contributions of individual core size fractions towards signal generation. Applying our method to two different experimental MNP systems, we found the most dominant contributions from approx. 20 nm sized particles in the two independent MNP systems. Additional comparison between freely suspended and immobilized MNP also reveals insight in the MNP microstructure, allowing to use FMMD for MNP characterization, as well as to further fine-tune its applicability in biosensing. Y1 - 2022 U6 - http://dx.doi.org/10.1016/j.jmmm.2022.169965 SN - 0304-8853 VL - 563 IS - In progress, Art. No. 169965 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Emons, H. A1 - Hüllenkremer, B. A1 - Schöning, Michael Josef T1 - Detection of metal ions in aqueous solutions by voltohmmetry JF - Fresenius' Journal of Analytical Chemistry. 369 (2001), H. 1 Y1 - 2001 SN - 0937-0633 SP - 42 EP - 46 ER - TY - JOUR A1 - Emons, H. A1 - Glück, O. A1 - Schöning, Michael Josef T1 - Voltohmmetry – An alternative detection principle at ultrathin metal electrodes in solution JF - Chemical and biological sensors and analytical methods : proceedings of the international symposium / Sensor, Physical Electrochemistry, and Organic and Biological Electrochemistry Divisions. Ed.: M. Butler Y1 - 2001 SN - 1-56677-351-2 N1 - International Symposium: Chemical and Biological Sensors and Analytical Methods ; (2 : 2001.) SP - 1 EP - 3 PB - Electrochemical Society CY - Pennington, NJ ER - TY - JOUR A1 - Emons, H. A1 - Glück, O. A1 - Hüllenkremer, B. A1 - Schöning, Michael Josef T1 - Voltohmmetry as an alternative detection method at polycrystalline metal film electrodes JF - Electroanalysis. 13 (2001), H. 8-9 Y1 - 2001 SN - 1040-0397 SP - 677 EP - 680 ER - TY - JOUR A1 - Emons, H. A1 - Baade, A. A1 - Schöning, Michael Josef T1 - Voltammetric determination of heavy metals in microvolumes of rain water JF - Electroanalysis. 12 (2000), H. 15 Y1 - 2000 SN - 1040-0397 SP - 1171 EP - 1176 ER - TY - JOUR A1 - Doll, Theodor A1 - Wagner, Torsten A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Engineering of functional interfaces / Theodor Doll ; Torsten Wagner ; Patrick Wagner ; Michael J. Schöning (eds.) JF - Physica status solidi (a) Y1 - 2016 U6 - http://dx.doi.org/10.1002/pssa.201670641 SN - 1862-6319 VL - 213 IS - 6 SP - 1393 EP - 1394 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Deppe, Veronika Maria A1 - Klatte, Stephanie A1 - Bongaerts, Johannes A1 - Maurer, Karl-Heinz A1 - O'Connell, Timothy A1 - Meinhardt, Friedhelm T1 - Genetic control of Amadori product degradation in Bacillus subtilis via regulation of frlBONMD expression by FrlR JF - Applied and environmental microbiology Y1 - 2011 SN - 1098-5336 (E-Journal); 0003-6919 (Print); 0099-2240 (Print) VL - Vol. 77 IS - No. 9 SP - 2839 EP - 2846 PB - American Society of Mechanical Engineers (ASME) CY - New York ER - TY - JOUR A1 - Deppe, Veronika Maria A1 - Bongaerts, Johannes A1 - O'Connell, Timothy A1 - Maurer, Karl-Heinz A1 - Meinhardt, Friedhelm T1 - Enzymatic deglycation of Amadori products in bacteria JF - Applied microbiology and biotechnology Y1 - 2011 SN - 1432-0614 (E-Journal); 0171-1741 (Print); 0175-7598 (Print); 0340-2118 (Print) VL - Vol. 90 IS - Iss. 2 SP - 399 EP - 406 PB - Springer CY - Berlin ER - TY - JOUR A1 - Delle, Lotta E. A1 - Huck, Christina A1 - Bäcker, Matthias A1 - Müller, Frank A1 - Grandthyll, Samuel A1 - Jacobs, Karin A1 - Lilischkis, Rainer A1 - Vu, Xuan T. A1 - Schöning, Michael Josef A1 - Wagner, Patrick A1 - Thoelen, Roland A1 - Weil, Maryam A1 - Ingebrandt, Sven T1 - Impedimetric immunosensor for the detection of histamine based on reduced graphene oxide JF - Physica status solidi (a) Y1 - 2015 U6 - http://dx.doi.org/10.1002/pssa.201431863 SN - 1862-6319 VL - 212 IS - 6 SP - 1327 EP - 1334 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Degering, Christian A1 - Eggert, Thorsten A1 - Puls, Michael A1 - Bongaerts, Johannes A1 - Evers, Stefan A1 - Maurer, Karl-Heinz A1 - Jaeger, Karl-Erich T1 - Optimization of protease secretion in Bacillus subtilis and Bacillus licheniformis by screening of homologous and herologous signal peptides JF - Applied and environmental microbiology N2 - Bacillus subtilis and Bacillus licheniformis are widely used for the large-scale industrial production of proteins. These strains can efficiently secrete proteins into the culture medium using the general secretion (Sec) pathway. A characteristic feature of all secreted proteins is their N-terminal signal peptides, which are recognized by the secretion machinery. Here, we have studied the production of an industrially important secreted protease, namely, subtilisin BPN′ from Bacillus amyloliquefaciens. One hundred seventy-three signal peptides originating from B. subtilis and 220 signal peptides from the B. licheniformis type strain were fused to this secretion target and expressed in B. subtilis, and the resulting library was analyzed by high-throughput screening for extracellular proteolytic activity. We have identified a number of signal peptides originating from both organisms which produced significantly increased yield of the secreted protease. Interestingly, we observed that levels of extracellular protease were improved not only in B. subtilis, which was used as the screening host, but also in two different B. licheniformis strains. To date, it is impossible to predict which signal peptide will result in better secretion and thus an improved yield of a given extracellular target protein. Our data show that screening a library consisting of homologous and heterologous signal peptides fused to a target protein can identify more-effective signal peptides, resulting in improved protein export not only in the original screening host but also in different production strains. Y1 - 2010 U6 - http://dx.doi.org/10.1128/AEM.01146-10 SN - 1098-5336 (E-Journal); 0003-6919 (Print); 0099-2240 (Print) VL - 76 IS - 19 SP - 6370 EP - 6378 PB - American Society for Microbiology CY - Washington, DC ER - TY - JOUR A1 - Darmo, J. A1 - Schäffer, F. A1 - Förster, Arnold A1 - Kordos, P. T1 - Beryllium doped low-temperature-grown MBE GaAs: material for photomixing in the THz frequency range JF - ASDAM 2000 : conference proceedings / edited by Jozef Osvald ... [et al.] Y1 - 2000 SN - 0780359399 N1 - International Conference on Advanced Semiconductor Devices and Microsystems ; (3rd : ; 2000 : ; Smolenice, Slovakia) SP - 147 EP - 150 PB - IEEE CY - Piscataway, NJ ER - TY - JOUR A1 - Dantism, Shahriar A1 - Takenaga, Shoko A1 - Wagner, Torsten A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Differential imaging of the metabolism of bacteria and eukaryotic cells based on light-addressable potentiometric sensors JF - Electrochimica Acta N2 - A light-addressable potentiometric sensor (LAPS) is a field-effect-based potentiometric sensor with an electrolyte/insulator/semiconductor (EIS) structure, which is able to monitor analyte concentrations of (bio-)chemical species in aqueous solutions in a spatially resolved way. Therefore, it is also an appropriate tool to record 2D-chemical images of concentration variations on the sensor surface. In the present work, two differential, LAPS-based measurement principles are introduced to determine the metabolic activity of Escherichia coli (E. coli) K12 and Chinese hamster ovary (CHO) cells as test microorganisms. Hereby, we focus on i) the determination of the extracellular acidification rate (ΔpH/min) after adding glucose solutions to the cell suspensions; and ii) recording the amplitude increase of the photocurrent (Iph) related to the produced acids from E. coli K12 bacteria and CHO cells on the sensor surface by 2D-chemical imaging. For this purpose, 3D-printed multi-chamber structures were developed and mounted on the planar sensor-chip surface to define four independent compartments, enabling differential measurements with varying cell concentrations. The differential concept allows eliminating unwanted drift effects and, with the four-chamber structures, measurements on the different cell concentrations were performed simultaneously, thus reducing also the overall measuring time. Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.electacta.2017.05.196 SN - 0013-4686 VL - 246 SP - 234 EP - 241 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Dantism, Shahriar A1 - Takenaga, Shoko A1 - Wagner, Patrick A1 - Wagner, Torsten A1 - Schöning, Michael Josef T1 - Determination of the extracellular acidification of Escherichia coli K12 with a multi-​chamber-​based LAPS system JF - Physica status solidi (a) N2 - On-line monitoring of the metabolic activity of microorganisms involved in intermediate stages of biogas production plays an important role to avoid undesirable “down times” during the biogas production. In order to control this process, an on-chip differential measuring system based on the light-addressable potentiometric sensor (LAPS) principle combined with a 3D-printed multi-chamber structure has been realized. As a test microorganism, Escherichia coli K12 (E. coli K12) were used for cell-based measurements. Multi-chamber structures were developed to determine the metabolic activity of E. coli K12 in suspension for a different number of cells, responding to the addition of a constant or variable amount of glucose concentrations, enabling differential and simultaneous measurements. Y1 - 2016 U6 - http://dx.doi.org/10.1002/pssa.201533043 SN - 1862-6300 VL - 213 IS - 6 SP - 1479 EP - 1485 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Dantism, Shahriar A1 - Röhlen, Desiree A1 - Wagner, Torsten A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Optimization of Cell-Based Multi-Chamber LAPS Measurements Utilizing FPGA-Controlled Laser-Diode Modules JF - physica status solidi a : applications and materials sciences N2 - A light-addressable potentiometric sensor (LAPS) is a field-effect-based potentiometric device, which detects concentration changes of an analyte solution on the sensor surface in a spatially resolved way. It uses a light source to generate electron–hole pairs inside the semiconductor, which are separated in the depletion region due to an applied bias voltage across the sensor structure and hence, a surface-potential-dependent photocurrent can be read out. However, depending on the beam angle of the light source, scattering effects can occur, which influence the recorded signal in LAPS-based differential measurements. To solve this problem, a novel illumination unit based on a field programmable gate array (FPGA) consisting of 16 small-sized tunable infrared laser-diode modules (LDMs) is developed. Due to the improved focus of the LDMs with a beam angle of only 2 mrad, undesirable scattering effects are minimized. Escherichia coli (E. coli) K12 bacteria are used as a test microorganism to study the extracellular acidification on the sensor surface. Furthermore, a salt bridge chamber is built up and integrated with the LAPS system enabling multi-chamber differential measurements with a single Ag/AgCl reference electrode. Y1 - 2018 U6 - http://dx.doi.org/10.1002/pssa.201800058 SN - 1862-6319 VL - 215 IS - 15 SP - Article number 1800058 PB - Wiley-VCH CY - Weinheim ER -