@article{WernerSchusserSpalthahnetal.2011, author = {Werner, Frederik and Schusser, Sebastian and Spalthahn, Heiko and Wagner, Torsten and Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef}, title = {Field-programmable gate array based controller for multi spot light-addressable potentiometric sensors with integrated signal correction mode}, series = {Electrochimica Acta}, volume = {56}, journal = {Electrochimica Acta}, number = {26}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0013-4686}, doi = {10.1016/j.electacta.2011.03.012}, pages = {9656 -- 9660}, year = {2011}, abstract = {A light-addressable potentiometric sensor (LAPS) can measure the concentration of one or several analytes at the sensor surface simultaneously in a spatially resolved manner. A modulated light pointer stimulates the semiconductor structure at the area of interest and a responding photocurrent can be read out. By simultaneous stimulation of several areas with light pointers of different modulation frequencies, the read out can be performed at the same time. With the new proposed controller electronic based on a field-programmable gate array (FPGA), it is possible to control the modulation frequencies, phase shifts, and light brightness of multiple light pointers independently and simultaneously. Thus, it is possible to investigate the frequency response of the sensor, and to examine the analyte concentration by the determination of the surface potential with the help of current/voltage curves and phase/voltage curves. Additionally, the ability to individually change the light intensities of each light pointer is used to perform signal correction.}, language = {en} } @inproceedings{WernerMansourRateikeetal.2011, author = {Werner, Frederik and Mansour, Ahmed and Rateike, Franz-Matthias and Schusser, Sebastian and Wagner, Torsten and Yoshinobu, Tatsuo and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Kompakter Aufbau eines lichtadressierbaren potentiometrischen Sensors mit verfahrbarem Diodenlaser}, series = {10. Dresdner Sensor-Symposium : Dresden, 5. - 7. Dezember 2011 ; miniaturisierte analytische Verfahren, Hochtemperatur-Sensoren, Sensoren f{\"u}r Bioprozess- und Verfahrenstechnik, Sensoren f{\"u}r die Medizin, Chemische Verfahrenstechnik, Lebensmittelanalytik, innovative Sensorl{\"o}sungen, Sensoren f{\"u}r die Wasserqualit{\"a}t, Selbst{\"u}berwachung / Gerald Gerlach ... (Hg.) Dresdner Beitr{\"a}ge zur Sensorik. 43}, booktitle = {10. Dresdner Sensor-Symposium : Dresden, 5. - 7. Dezember 2011 ; miniaturisierte analytische Verfahren, Hochtemperatur-Sensoren, Sensoren f{\"u}r Bioprozess- und Verfahrenstechnik, Sensoren f{\"u}r die Medizin, Chemische Verfahrenstechnik, Lebensmittelanalytik, innovative Sensorl{\"o}sungen, Sensoren f{\"u}r die Wasserqualit{\"a}t, Selbst{\"u}berwachung / Gerald Gerlach ... (Hg.) Dresdner Beitr{\"a}ge zur Sensorik. 43}, editor = {Gerlach, Gerald}, publisher = {TUDpress}, address = {Dresden}, isbn = {978-3-942710-53-4}, pages = {277 -- 280}, year = {2011}, language = {de} } @phdthesis{Schusser2015, author = {Schusser, Sebastian}, title = {Sensor-based degradation monitoring for the evaluation of (bio)degradable polymers}, publisher = {Universiteit Hasselt ; FH Aachen}, address = {Hasselt ; Aachen}, pages = {145 Seiten}, year = {2015}, language = {en} } @article{SchusserBaeckerKrischeretal.2014, author = {Schusser, Sebastian and B{\"a}cker, Matthias and Krischer, M. and Wenzel, L. and Leinhos, Marcel and Poghossian, Arshak and Biselli, Manfred and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Enzymatically catalyzed degradation of biodegradable polymers investigated by means of a semiconductor-based field-effect sensor}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.689}, pages = {1314 -- 1317}, year = {2014}, abstract = {A semiconductor field-effect device has been used for an enzymatically catalyzed degradation of biopolymers for the first time. This novel technique is capable to monitor the degradation process of multiple samples in situ and in real-time. As model system, the degradation of the biopolymer poly(D, L-lactic acid) has been monitored in the degradation medium containing the enzyme lipase from Rhizomucor miehei. The obtained results demonstrate the potential of capacitive field-effect sensors for degradation studies of biodegradable polymers.}, language = {en} } @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} } @inproceedings{BaeckerSchusserLeinhosetal.2014, author = {B{\"a}cker, Matthias and Schusser, Sebastian and Leinhos, Marcel and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Sensor system for the monitoring of degradation processes of biodegradable biopolymers}, series = {Sensoren und Messsysteme 2014 ; Beitr{\"a}ge der 17. GMA/ITG-Fachtagung vom 3. bis 4. Juni 2014 in N{\"u}rnberg. (ITG-Fachbericht ; 250)}, booktitle = {Sensoren und Messsysteme 2014 ; Beitr{\"a}ge der 17. GMA/ITG-Fachtagung vom 3. bis 4. Juni 2014 in N{\"u}rnberg. (ITG-Fachbericht ; 250)}, publisher = {VDE-Verl.}, address = {D{\"u}sseldorf}, organization = {VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik}, isbn = {978-3-8007-3622-5}, pages = {1 -- 4}, year = {2014}, language = {en} } @article{BaeckerSchusserPoghossianetal.2013, author = {B{\"a}cker, Matthias and Schusser, Sebastian and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Degradationsverhalten bioabbaubarer Polymere : siliziumbasierte Sensorik zur {\"U}berwachung}, series = {GIT Labor-Fachzeitschrift}, journal = {GIT Labor-Fachzeitschrift}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0016-3538}, pages = {32 -- 33}, year = {2013}, language = {de} } @article{LeinhosSchusserBaeckeretal.2014, author = {Leinhos, Marcel and Schusser, Sebastian and B{\"a}cker, Matthias and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Micromachined multi-parameter sensor chip for the control of polymer-degradation medium}, series = {Physica Status Solidi (A) : special issue on engineering and functional interfaces}, volume = {211}, journal = {Physica Status Solidi (A) : special issue on engineering and functional interfaces}, number = {6}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-396X (E-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330364}, pages = {1346 -- 1351}, year = {2014}, abstract = {It is well known that the degradation environment can strongly influence the biodegradability and kinetics of biodegradation processes of polymers. Therefore, besides the monitoring of the degradation process, it is also necessary to control the medium in which the degradation takes place. In this work, a micromachined multi-parameter sensor chip for the control of the polymer-degradation medium has been developed. The chip combines a capacitive field-effect pH sensor, a four-electrode electrolyte-conductivity sensor and a thin-film Pt-temperature sensor. The results of characterization of individual sensors are presented. In addition, the multi-parameter sensor chip together with an impedimetric polymer-degradation sensor was simultaneously characterized in degradation solutions with different pH and electrolyte conductivity. The obtained results demonstrate the feasibility of the multi-parameter sensor chip for the control of the polymer-degradation medium.}, language = {en} } @article{SchusserMenzelBaeckeretal.2013, author = {Schusser, Sebastian and Menzel, S. and B{\"a}cker, Matthias and Leinhos, Marcel and Poghossian, Arshak and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Degradation of thin poly(lactic acid) films: characterization by capacitance-voltage, atomic force microscopy, scanning electron microscopy and contact-angle measurements}, series = {Electrochimica Acta}, volume = {Vol. 113}, journal = {Electrochimica Acta}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3859 (E-Journal); 0013-4686 (Print)}, pages = {779 -- 784}, year = {2013}, language = {en} } @article{SchusserPoghossianBaeckeretal.2015, author = {Schusser, Sebastian and Poghossian, Arshak and B{\"a}cker, Matthias and Krischer, M. and Leinhos, Marcel and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {An application of field-effect sensors for in-situ monitoring of degradation of biopolymers}, series = {Sensors and actuators B: Chemical}, volume = {207, Part B}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.10.058}, pages = {954 -- 959}, year = {2015}, abstract = {The characterization of the degradation kinetics of biodegradable polymers is mandatory with regard to their proper application. In the present work, polymer-modified electrolyte-insulator-semiconductor (PMEIS) field-effect sensors have been applied for in-situ monitoring of the pH-dependent degradation kinetics of the commercially available biopolymer poly(d,l-lactic acid) (PDLLA) in buffer solutions from pH 3 to pH 13. PDLLA films of 500 nm thickness were deposited on the surface of an Al-p-Si-SiO2-Ta2O5 structure from a polymer solution by means of spin-coating method. The PMEIS sensor is, in principle, capable to detect any changes in bulk, surface and interface properties of the polymer induced by degradation processes. A faster degradation has been observed for PDLLA films exposed to alkaline solutions (pH 9, pH 11 and pH 13).}, language = {en} }