TY  - JOUR
A1  - Huck, Christina
A1  - Poghossian, Arshak
A1  - Kerroumi, Iman
A1  - Schusser, Sebastian
A1  - Bäcker, Matthias
A1  - Zander, Willi
A1  - Schubert, Jürgen
A1  - Buniatyan, Vahe V.
A1  - Martirosyan, Norayr W.
A1  - Wagner, Patrick
A1  - Schöning, Michael Josef
T1  - Multiparameter sensor chip with Barium Strontium Titanate as multipurpose material
JF  - Electroanalysis
N2  - 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.
Y1  - 2014
U6  - http://dx.doi.org/10.1002/elan.201400076
SN  - 1521-4109 (E-Journal); 1040-0397 (Print)
VL  - 26
IS  - 5
SP  - 980
EP  - 987
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Murib, Mohammed Sharif
A1  - Yeap, Weng-Siang
A1  - Martens, Daan
A1  - Bienstman, Peter
A1  - Ceuninck, Ward de
A1  - Grinsven, Bart van
A1  - Schöning, Michael Josef
A1  - Michiels, Luc
A1  - Haenen, Ken
A1  - Ameloot, Marcel
A1  - Serpengüzel, Ali
A1  - Wagner, Patrick
T1  - Photonic detection and characterization of DNA using sapphire microspheres
JF  - Journal of biomedical optics
N2  - 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.
Y1  - 2014
U6  - http://dx.doi.org/10.1117/1.JBO.19.9.097006
SN  - 1560-2281 (E-Journal); 1083-3668 (Print)
VL  - 19
IS  - 9
SP  - 097006
PB  - SPIE
CY  - Bellingham
ER  - 
TY  - JOUR
A1  - Wagner, Patrick
A1  - Doll, Theodor
A1  - Schöning, Michael Josef
T1  - Engineering of functional interfaces / Patrick Wagner ; Theodor Doll ; Michael J. Schöning (eds.)
JF  - Physica status solidi (A) : Applications and materials science
Y1  - 2014
U6  - http://dx.doi.org/10.1002/pssa.201470241
SN  - 1521-396X (E-Book); 1862-6319 (E-Book); 0031-8965 (Print); 1862-6300 (Print)
VL  - 211
IS  - 6
SP  - 1339
EP  - 1339
PB  - Wiley-VCH
CY  - Weinheim
ER  -