TY - JOUR A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Siqueira, José R. Jr. A1 - Oliveira, Osvaldo N. Jr. A1 - Moritz, Werner A1 - Schöning, Michael Josef T1 - Capacitive electrolyte-insulator-semiconductor structures functionalised with a polyelectrolyte/enzyme multilayer: New strategy for enhanced field-effect biosensing JF - Physica Status Solidi (A). 207 (2010), H. 4 Y1 - 2010 SN - 1862-6300 N1 - Special Issue: Engineering of Functional Interfaces EnFI 2009 SP - 884 EP - 890 ER - TY - JOUR A1 - Siqueira, José R. Jr. A1 - Abouzar, Maryam H. A1 - Poghossian, Arshak A1 - Zucolotto, Valtencir A1 - Oliveira, Osvaldo N. Jr. A1 - Schöning, Michael Josef T1 - Penicillin biosensor based on a capacitive field-effect structure functionalized with a dendrimer/carbon nanotube multilayer JF - Biosensors and Bioelectronics. 25 (2009), H. 2 Y1 - 2009 SN - 0956-5663 SP - 497 EP - 501 ER - TY - JOUR A1 - Siqueira, José R. Jr. A1 - Bäcker, Matthias A1 - Poghossian, Arshak A1 - Zucolotto, Valtencir A1 - Oliveira, Osvaldo N. Jr. A1 - Schöning, Michael Josef T1 - Associating biosensing properties with the morphological structure of multilayers containing carbon nanotubes on field-effect devices JF - Physica status solidi (a). 207 (2010), H. 4 Y1 - 2010 SN - 1862-6300 N1 - Special Issue: Engineering of Functional Interfaces EnFI 2009 SP - 781 EP - 786 ER - TY - JOUR A1 - Gasparyan, Ferdinand V. A1 - Poghossian, Arshak A1 - Vitusevich, Svetlana A. A1 - Petrychuk, Mykhaylo V. A1 - Sydoruk, Viktor A. A1 - Siqueira, José R. Jr. A1 - Oliveira, Osvaldo N. Jr. A1 - Offenhäusser, Andreas A1 - Schöning, Michael Josef T1 - Low-Frequency Noise in Field-Effect Devices Functionalized With Dendrimer/Carbon-Nanotube Multilayers JF - IEEE Sensors Journal. 11 (2011), H. 1 Y1 - 2011 SN - 1530-437X SP - 142 EP - 149 PB - IEEE CY - New York ER - TY - JOUR A1 - Siqueira, José R. Jr. A1 - Abouzar, Maryam H. A1 - Bäcker, Matthias A1 - Zucolotto, Valtencir A1 - Poghossian, Arshak A1 - Oliveira, Osvaldo N. Jr. A1 - Schöning, Michael Josef T1 - Carbon nanotubes in nanostructured films: Potential application as amperometric and potentiometric field-effect (bio-)chemical sensors JF - physica status solidi (a) . 206 (2009), H. 3 Y1 - 2009 SN - 1862-6319 N1 - Special Issue: Engineering of Functional Interfaces (EnFI 08) SP - 462 EP - 467 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Sousa, Marcos A. M. A1 - Siqueira, Jose R. Jr. A1 - Vercik, Andres A1 - Schöning, Michael Josef A1 - Oliveira, Osvaldo N. Jr. T1 - Determining the optimized layer-by-layer film architecture with dendrimer/carbon nanotubes for field-effect sensors JF - IEEE Sensors Journal N2 - The capacitive electrolyte–insulator–semiconductor (EIS) structure is a typical device based on a field-effect sensor platform. With a simple silicon-based structure, EIS have been useful for several sensing applications, especially with incorporation of nanostructured films to modulate the ionic transport and the flat-band potential. In this paper, we report on ion transport and changes in flat-band potential in EIS sensors made with layer-by-layer films containing poly(amidoamine) (PAMAM) dendrimer and single-walled carbon nanotubes (SWNTs) adsorbed on p-Si/SiO 2 /Ta 2 O 5 chips with an Al ohmic contact. The impedance spectra were fitted using an equivalent circuit model, from which we could determine parameters such as the double-layer capacitance. This capacitance decreased with the number of bilayers owing to space charge accumulated at the electrolyte–insulator interface, up to three PAMAM/SWNTs bilayers, after which it stabilized. The charge-transfer resistance was also minimum for three bilayers, thus indicating that this is the ideal architecture for an optimized EIS performance. The understanding of the influence of nanostructures and the fine control of operation parameters pave the way for optimizing the design and performance of new EIS sensors. Y1 - 2017 U6 - https://doi.org/10.1109/JSEN.2017.2653238 SN - 1558-1748 VL - 17 IS - 6 SP - 1735 EP - 1740 PB - IEEE CY - New York ER - TY - JOUR A1 - Morais, Paulo V. A1 - Gomes, Vanderley F., Jr. A1 - Silva, Anielle C. A. A1 - Dantas, Noelio O. A1 - Schöning, Michael Josef A1 - Siqueira, José R., Jr. T1 - Nanofilm of ZnO nanocrystals/carbon nanotubes as biocompatible layer for enzymatic biosensors in capacitive field-effect devices JF - Journal of Materials Science N2 - The incorporation of nanomaterials that are biocompatible with different types of biological compounds has allowed the development of a new generation of biosensors applied especially in the biomedical field. In particular, the integration of film-based nanomaterials employed in field-effect devices can be interesting to develop biosensors with enhanced properties. In this paper, we studied the fabrication of sensitive nanofilms combining ZnO nanocrystals and carbon nanotubes (CNTs), prepared by means of the layer-by-layer (LbL) technique, in a capacitive electrolyte-insulator-semiconductor (EIS) structure for detecting glucose and urea. The ZnO nanocrystals were incorporated in a polymeric matrix of poly(allylamine) hydrochloride (PAH), and arranged with multi-walled CNTs in a LbL PAH-ZnO/CNTs film architecture onto EIS chips. The electrochemical characterizations were performed by capacitance–voltage and constant capacitance measurements, while the morphology of the films was characterized by atomic force microscopy. The enzymes glucose oxidase and urease were immobilized on film’s surface for detection of glucose and urea, respectively. In order to obtain glucose and urea biosensors with optimized amount of sensitive films, we investigated the ideal number of bilayers for each detection system. The glucose biosensor showed better sensitivity and output signal for an LbL PAH-ZnO/CNTs nanofilm with 10 bilayers. On the other hand, the urea biosensor presented enhanced properties even for the first bilayer, exhibiting high sensitivity and output signal. The presence of the LbL PAH-ZnO/CNTs films led to biosensors with better sensitivity and enhanced response signal, demonstrating that the adequate use of nanostructured films is feasible for proof-of-concept biosensors with improved properties that may be employed for biomedical applications. Y1 - 2017 U6 - https://doi.org/10.1007/s10853-017-1369-y SN - 1573-4803 VL - 52 IS - 20 SP - 12314 EP - 12325 PB - Springer CY - Berlin ER - TY - JOUR A1 - Siqueira, Jose R. A1 - Maki, Rafael M. A1 - Paulovich, Fernando V. A1 - Werner, Frederik A1 - Poghossian, Arshak A1 - Oliveira, Maria C. F. de A1 - Zucolotto, Valtencir A1 - Oliveira, Osvaldo N. Jr. A1 - Schöning, Michael Josef T1 - Use of Information Visualization Methods Eliminating Cross Talk in Multiple Sensing Units Investigated for a Light-Addressable Potentiometric Sensor JF - Analytical Chemistry (2010) Y1 - 2010 SN - 0003-2700 SP - 61 EP - 65 ER - TY - JOUR A1 - Siqueira, Jose R. A1 - Werner, Frederik A1 - Bäcker, Matthias A1 - Poghossian, Arshak A1 - Zucolotto, Valtencir A1 - Oliveira, Osvaldo N. Jr. A1 - Schöning, Michael Josef T1 - Layer-by-Layer Assembly of Carbon Nanotubes Incorporated in Light-Addressable Potentiometric Sensors JF - Journal of Physical Chemistry C. 113 (2009), H. 33 Y1 - 2009 SN - 1932-7455 SP - 14765 EP - 14770 PB - American Chemical Society CY - Washington, DC ER - TY - JOUR A1 - Morais, Paulo V. A1 - Silva, Anielle C. A. A1 - Dantas, Noelio O. A1 - Schöning, Michael Josef A1 - Siqueira, José R., Jr. T1 - Hybrid Layer‐by‐Layer Film of Polyelectrolytes‐Embedded Catalytic CoFe2O4 Nanocrystals as Sensing Units in Capacitive Electrolyte‐Insulator‐Semiconductor Devices JF - physica status solidi a : applications and materials sciences Y1 - 2019 U6 - https://doi.org/10.1002/pssa.201900044 VL - 216 IS - 1900044 SP - 1 EP - 9 PB - Wiley CY - Weinheim ER -