@article{BaeckerRaueSchusseretal.2012, author = {B{\"a}cker, Matthias and Raue, Markus and Schusser, Sebastian and Jeitner, C. and Breuer, L. and Wagner, P. and Poghossian, Arshak and F{\"o}rster, Arnold and Mang, Thomas and Sch{\"o}ning, Michael Josef}, title = {Microfluidic chip with integrated microvalves based on temperature- and pH-responsive hydrogel thin films}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100763}, pages = {839 -- 845}, year = {2012}, abstract = {Two types of microvalves based on temperature-responsive poly(N-isopropylacrylamide) (PNIPAAm) and pH-responsive poly(sodium acrylate) (PSA) hydrogel films have been developed and tested. The PNIPAAm and PSA hydrogel films were prepared by means of in situ photopolymerization directly inside the fluidic channel of a microfluidic chip fabricated by combining Si and SU-8 technologies. The swelling/shrinking properties and height changes of the PNIPAAm and PSA films inside the fluidic channel were studied at temperatures of deionized water from 14 to 36 °C and different pH values (pH 3-12) of Titrisol buffer, respectively. Additionally, in separate experiments, the lower critical solution temperature (LCST) of the PNIPAAm hydrogel was investigated by means of a differential scanning calorimetry (DSC) and a surface plasmon resonance (SPR) method. Mass-flow measurements have shown the feasibility of the prepared hydrogel films to work as an on-chip integrated temperature- or pH-responsive microvalve capable to switch the flow channel on/off.}, language = {en} } @article{AridaMohsenSchoening2009, author = {Arida, Hassan and Mohsen, Q. and Sch{\"o}ning, Michael Josef}, title = {Microfabrication, characterization and analytical application of a new thin-film silver microsensor}, series = {Electrochimica Acta. 54 (2009), H. 13}, journal = {Electrochimica Acta. 54 (2009), H. 13}, isbn = {0013-4686}, pages = {3543 -- 3547}, year = {2009}, language = {en} } @article{SchoeningLueth2002, author = {Sch{\"o}ning, Michael Josef and L{\"u}th, H.}, title = {Microfabricated semiconductor structures - Advances in (bio-)chemical sensing}, series = {Coupling of biological and electronic systems : proceedings of the 2nd Caesarium, Bonn, November 1 - 3, 2000 / Karl-Heinz Hoffmann, ed.}, journal = {Coupling of biological and electronic systems : proceedings of the 2nd Caesarium, Bonn, November 1 - 3, 2000 / Karl-Heinz Hoffmann, ed.}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {3-540-43699-5}, pages = {79 -- 92}, year = {2002}, language = {en} } @article{Schoening2001, author = {Sch{\"o}ning, Michael Josef}, title = {Microelectronics contacts (bio-)chemistry - Semiconductor-based sensors}, series = {Biologi Italiani. 8 (2001)}, journal = {Biologi Italiani. 8 (2001)}, isbn = {0392-2510}, pages = {5 -- 10}, year = {2001}, language = {en} } @article{SchoeningGlueckSchrothetal.1999, author = {Sch{\"o}ning, Michael Josef and Gl{\"u}ck, O. and Schroth, P. and Sch{\"u}tz, S. (u.a.)}, title = {Microelectrodes, capacitors and BioFETs: Novel trends in silicon-based biochemical sensing}, series = {Biocybernetics and Biomedical Engineering. 19 (1999), H. 1}, journal = {Biocybernetics and Biomedical Engineering. 19 (1999), H. 1}, issn = {0208-5216}, pages = {105 -- 126}, year = {1999}, language = {en} } @article{SchmittWernerSchoening2002, author = {Schmitt, G. and Werner, C. and Sch{\"o}ning, Michael Josef}, title = {Microelectrochemical efficiency evaluation of inhibitors for CO2 corrosion of carbon steel under high shear stress gradients}, series = {Corrosion 2002. Conference Proceedings. NACExpo, 57th Annual Conference and Exhibition, Denver, US, Apr 7-11, 2002}, journal = {Corrosion 2002. Conference Proceedings. NACExpo, 57th Annual Conference and Exhibition, Denver, US, Apr 7-11, 2002}, publisher = {NACE International}, address = {Houston, Texas}, pages = {1 -- 11}, year = {2002}, language = {en} } @article{SchoeningSchrothHummeletal.2001, author = {Sch{\"o}ning, Michael Josef and Schroth, P. and Hummel, Hans E. and Weißbecker, B. and L{\"u}th, H. and Sch{\"u}tz, S.}, title = {Microcsaled living bioelectronic systems - Coupling beetles to silicon transducers}, series = {Chemical and biological sensors and analytical methods : proceedings of the international symposium / Sensor, Physical Electrochemistry, and Organic and Biological Electrochemistry Divisions. Ed.: M. Butler}, journal = {Chemical and biological sensors and analytical methods : proceedings of the international symposium / Sensor, Physical Electrochemistry, and Organic and Biological Electrochemistry Divisions. Ed.: M. Butler}, publisher = {Electrochemical Society}, address = {Pennington, NJ}, isbn = {1-56677-351-2}, pages = {165 -- 173}, year = {2001}, language = {en} } @article{KurowskiSchultzeLuethetal.2002, author = {Kurowski, A. and Schultze, J. and L{\"u}th, H. and Sch{\"o}ning, Michael Josef}, title = {Micro- and nanopatterning of sensor chips by means of macroporous silicon.}, series = {Sensors and Actuators B. 83 (2002), H. 1-3}, journal = {Sensors and Actuators B. 83 (2002), H. 1-3}, isbn = {0925-4005}, pages = {123 -- 128}, year = {2002}, language = {en} } @article{KurowskiSchultzeLuethetal.2001, author = {Kurowski, A. and Schultze, J.W. and L{\"u}th, H. and Sch{\"o}ning, Michael Josef}, title = {Micro- and nanopatterning of sensor chips by means of macroporous silicon}, series = {Transducers '01 Eurosensors XV : digest of technical papers / the 11th International Conference on Solid-State Sensors and Actuators, June 10-14, 2001, Munich, Germany. Ernst Obermeier (Ed.)}, journal = {Transducers '01 Eurosensors XV : digest of technical papers / the 11th International Conference on Solid-State Sensors and Actuators, June 10-14, 2001, Munich, Germany. Ernst Obermeier (Ed.)}, publisher = {Springer}, address = {Berlin [u.a.]}, isbn = {3-540-42150-5}, pages = {640 -- 643}, year = {2001}, language = {en} } @article{HuckSchiffelsHerreraetal.2013, author = {Huck, Christina and Schiffels, Johannes and Herrera, Cony N. and Schelden, Maximilian and Selmer, Thorsten and Poghossian, Arshak and Baumann, Marcus and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Metabolic responses of Escherichia coli upon glucose pulses captured by a capacitive field-effect sensor}, series = {Physica Status Solidi (A)}, volume = {210}, journal = {Physica Status Solidi (A)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0031-8965}, doi = {10.1002/pssa.201200900}, pages = {926 -- 931}, year = {2013}, abstract = {Living cells are complex biological systems transforming metabolites taken up from the surrounding medium. Monitoring the responses of such cells to certain substrate concentrations is a challenging task and offers possibilities to gain insight into the vitality of a community influenced by the growth environment. Cell-based sensors represent a promising platform for monitoring the metabolic activity and thus, the "welfare" of relevant organisms. In the present study, metabolic responses of the model bacterium Escherichia coli in suspension, layered onto a capacitive field-effect structure, were examined to pulses of glucose in the concentration range between 0.05 and 2 mM. It was found that acidification of the surrounding medium takes place immediately after glucose addition and follows Michaelis-Menten kinetic behavior as a function of the glucose concentration. In future, the presented setup can, therefore, be used to study substrate specificities on the enzymatic level and may as well be used to perform investigations of more complex metabolic responses. Conclusions and perspectives highlighting this system are discussed.}, language = {en} }