@article{SchusserKrischerBaeckeretal.2015,
  author    = {Schusser, Sebastian and Krischer, Maximillian and B{\"a}cker, Matthias and Poghossian, Arshak and Wagner, Patrick and Sch{\"o}ning, Michael Josef},
  title     = {Monitoring of the Enzymatically Catalyzed Degradation of Biodegradable Polymers by Means of Capacitive Field-Effect Sensors},
  series = {Analytical Chemistry},
  volume    = {87},
  journal   = {Analytical Chemistry},
  number    = {13},
  publisher = {ACS Publications},
  address   = {Washington, DC},
  issn      = {1520-6882},
  doi       = {10.1021/acs.analchem.5b00617},
  pages     = {6607 -- 6613},
  year      = {2015},
  abstract  = {Designing novel or optimizing existing biodegradable polymers for biomedical applications requires numerous tests on the effect of substances on the degradation process. In the present work, polymer-modified electrolyte-insulator-semiconductor (PMEIS) sensors have been applied for monitoring an enzymatically catalyzed degradation of polymers for the first time. The thin films of biodegradable polymer poly(d,l-lactic acid) and enzyme lipase were used as a model system. During degradation, the sensors were read-out by means of impedance spectroscopy. In order to interpret the data obtained from impedance measurements, an electrical equivalent circuit model was developed. In addition, morphological investigations of the polymer surface have been performed by means of in situ atomic force microscopy. The sensor signal change, which reflects the progress of degradation, indicates an accelerated degradation in the presence of the enzyme compared to hydrolysis in neutral pH buffer media. The degradation rate increases with increasing enzyme concentration. The obtained results demonstrate the potential of PMEIS sensors as a very promising tool for in situ and real-time monitoring of degradation of polymers.},
  language  = {en}
}
@article{OberlaenderJildehKirchneretal.2015,
  author    = {Oberl{\"a}nder, Jan and Jildeh, Zaid B. and Kirchner, Patrick and Wendeler, Luisa and Bromm, Alexander and Iken, Heiko and Wagner, Patrick and Keusgen, Michael and Sch{\"o}ning, Michael Josef},
  title     = {Study of Interdigitated Electrode Arrays Using Experiments and Finite Element Models for the Evaluation of Sterilization Processes},
  series = {Sensors},
  volume    = {15},
  journal   = {Sensors},
  number    = {10},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1424-8220},
  doi       = {10.3390/s151026115},
  pages     = {26115 -- 26127},
  year      = {2015},
  abstract  = {In this work, a sensor to evaluate sterilization processes with hydrogen peroxide vapor has been characterized. Experimental, analytical and numerical methods were applied to evaluate and study the sensor behavior. The sensor set-up is based on planar interdigitated electrodes. The interdigitated electrode structure consists of 614 electrode fingers spanning over a total sensing area of 20 mm2. Sensor measurements were conducted with and without microbiological spores as well as after an industrial sterilization protocol. The measurements were verified using an analytical expression based on a first-order elliptical integral. A model based on the finite element method with periodic boundary conditions in two dimensions was developed and utilized to validate the experimental findings.},
  language  = {en}
}
@article{DelleHuckBaeckeretal.2015,
  author    = {Delle, Lotta E. and Huck, Christina and B{\"a}cker, Matthias and M{\"u}ller, Frank and Grandthyll, Samuel and Jacobs, Karin and Lilischkis, Rainer and Vu, Xuan T. and Sch{\"o}ning, Michael Josef and Wagner, Patrick and Thoelen, Roland and Weil, Maryam and Ingebrandt, Sven},
  title     = {Impedimetric immunosensor for the detection of histamine based on reduced graphene oxide},
  series = {Physica status solidi (a)},
  volume    = {212},
  journal   = {Physica status solidi (a)},
  number    = {6},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1862-6319},
  doi       = {10.1002/pssa.201431863},
  pages     = {1327 -- 1334},
  year      = {2015},
  language  = {en}
}
@article{WarmerWagnerSchoeningetal.2015,
  author    = {Warmer, Johannes and Wagner, Patrick and Sch{\"o}ning, Michael Josef and Kaul, Peter},
  title     = {Detection of triacetone triperoxide using temperature cycled metal-oxide semiconductor gas sensors},
  series = {Physica status solidi (a)},
  volume    = {212},
  journal   = {Physica status solidi (a)},
  number    = {6},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1862-6319},
  doi       = {10.1002/pssa.201431882},
  pages     = {1289 -- 1298},
  year      = {2015},
  language  = {en}
}
@article{MuribYeapMartensetal.2015,
  author    = {Murib, M. S. and Yeap, W. S. and Martens, D. and Liu, X. and Bienstman, P. and Fahlman, M. and Sch{\"o}ning, Michael Josef and Michiels, L. and Haenen, K. and Serpeng{\"u}zel, A. and Wagner, Patrick},
  title     = {Photonic studies on polymer-coated sapphire-spheres : a model system for biological ligands},
  series = {Sensors and actuators A: Physical},
  volume    = {222},
  journal   = {Sensors and actuators A: Physical},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1873-3069 (E-Journal); 0924-4247 (Print)},
  doi       = {10.1016/j.sna.2014.11.024},
  pages     = {212 -- 219},
  year      = {2015},
  abstract  = {In this study we show an optical biosensor concept, based on elastic light scattering from sapphire microspheres. Transmitted and elastic scattering intensity of the microspheres (radius 500 μm, refractive index 1.77) on an optical fiber half coupler is analyzed at 1510 nm. The 0.43 nm angular mode spacing of the resonances is comparable to the angular mode spacing value estimated using the optical size of the microsphere. The spectral linewidths of the resonances are in the order of 0.01 nm, which corresponds to quality factors of approximately 105. A polydopamine layer is used as a functionalizing agent on sapphire microspherical resonators in view of biosensor implementation. The varying layer thickness on the microsphere is determined as a function of the resonance wavelength shift. It is shown that polymer functionalization has a minor effect on the quality factor. This is a promising step toward the development of an optical biosensor.},
  language  = {en}
}
@article{MuribYeapMartensetal.2014,
  author    = {Murib, Mohammed Sharif and Yeap, Weng-Siang and Martens, Daan and Bienstman, Peter and Ceuninck, Ward de and Grinsven, Bart van and Sch{\"o}ning, Michael Josef and Michiels, Luc and Haenen, Ken and Ameloot, Marcel and Serpeng{\"u}zel, Ali and Wagner, Patrick},
  title     = {Photonic detection and characterization of DNA using sapphire microspheres},
  series = {Journal of biomedical optics},
  volume    = {19},
  journal   = {Journal of biomedical optics},
  number    = {9},
  publisher = {SPIE},
  address   = {Bellingham},
  issn      = {1560-2281 (E-Journal); 1083-3668 (Print)},
  doi       = {10.1117/1.JBO.19.9.097006},
  pages     = {097006},
  year      = {2014},
  abstract  = {A microcavity-based deoxyribonucleic acid (DNA) optical biosensor is demonstrated for the first time using synthetic sapphire for the optical cavity. Transmitted and elastic scattering intensity at 1510 nm are analyzed from a sapphire microsphere (radius 500  μm, refractive index 1.77) on an optical fiber half coupler. The 0.43 nm angular mode spacing of the resonances correlates well with the optical size of the sapphire sphere. Probe DNA consisting of a 36-mer fragment was covalently immobilized on a sapphire microsphere and hybridized with a 29-mer target DNA. Whispering gallery modes (WGMs) were monitored before the sapphire was functionalized with DNA and after it was functionalized with single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). The shift in WGMs from the surface modification with DNA was measured and correlated well with the estimated thickness of the add-on DNA layer. It is shown that ssDNA is more uniformly oriented on the sapphire surface than dsDNA. In addition, it is shown that functionalization of the sapphire spherical surface with DNA does not affect the quality factor (Q≈104) of the sapphire microspheres. The use of sapphire is especially interesting because this material is chemically resilient, biocompatible, and widely used for medical implants.},
  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{HuckPoghossianKerroumietal.2014,
  author    = {Huck, Christina and Poghossian, Arshak and Kerroumi, Iman and Schusser, Sebastian and B{\"a}cker, Matthias and Zander, Willi and Schubert, J{\"u}rgen and Buniatyan, Vahe V. and Martirosyan, Norayr W. and Wagner, Patrick and Sch{\"o}ning, Michael Josef},
  title     = {Multiparameter sensor chip with Barium Strontium Titanate as multipurpose material},
  series = {Electroanalysis},
  volume    = {26},
  journal   = {Electroanalysis},
  number    = {5},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1521-4109 (E-Journal); 1040-0397 (Print)},
  doi       = {10.1002/elan.201400076},
  pages     = {980 -- 987},
  year      = {2014},
  abstract  = {It is well known that biochemical and biotechnological processes are strongly dependent and affected by a variety of physico-chemical parameters such as pH value, temperature, pressure and electrolyte conductivity. Therefore, these quantities have to be monitored or controlled in order to guarantee a stable process operation, optimization and high yield. In this work, a sensor chip for the multiparameter detection of three physico-chemical parameters such as electrolyte conductivity, pH and temperature is realized using barium strontium titanate (BST) as multipurpose material. The chip integrates a capacitively coupled four-electrode electrolyte-conductivity sensor, a capacitive field-effect pH sensor and a thin-film Pt-temperature sensor. Due to the multifunctional properties of BST, it is utilized as final outermost coating layer of the processed sensor chip and serves as passivation and protection layer as well as pH-sensitive transducer material at the same time. The results of testing of the individual sensors of the developed multiparameter sensor chip are presented. In addition, a quasi-simultaneous multiparameter characterization of the sensor chip in buffer solutions with different pH value and electrolyte conductivity is performed. To study the sensor behavior and the suitability of BST as multifunctional material under harsh environmental conditions, the sensor chip was exemplarily tested in a biogas digestate.},
  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{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}
}