@article{YangKriechbaumerAlbrachtetal.2014, author = {Yang, Peng-Fei and Kriechbaumer, Andreas and Albracht, Kirsten and Sanno, Maximilian and Ganse, Bergita and Koy, Timmo and Shang, Peng and br{\"u}ggemann, Gert-Peter and M{\"u}ller, Lars Peter and Rittweger, J{\"o}rn}, title = {A novel optical approach for assessing in vivo bone segment deformation and its application in muscle-bone relationship studies in humans}, series = {Journal of Orthopaedic Translation}, volume = {2}, journal = {Journal of Orthopaedic Translation}, number = {4}, publisher = {Elsevier}, address = {Singapore}, issn = {2214-0328}, doi = {10.1016/j.jot.2014.07.078}, pages = {238 -- 238}, year = {2014}, language = {en} } @article{AkimbekovDigelOHerasetal.2014, author = {Akimbekov, N.Sh. and Digel, Ilya and O´Heras, C. and Tastambek, K.T. and Savitskaya, I.S. and Ualyeva, P.S. and Mansurov, Z.A. and Zhubanova, A.A.}, title = {Adsorption of bacterial lipopolysaccharides on carbonized rice husks obtained in the batch experiments}, series = {Experimental Biology}, volume = {60}, journal = {Experimental Biology}, number = {1/2}, publisher = {Al-Farabi Kazakh National University}, address = {Almaty}, issn = {1563-0218}, pages = {144 -- 148}, year = {2014}, abstract = {The scope of this study is the measurement of endotoxin adsorption rate for carbonized rice husk. It showed good adsorption properties for LPS. During the batch experiments, several techniques were used and optimized for improving the material's adsorption behavior. Also, with the results obtained it was possible to differentiate the materials according to their adsorption capacity and kinetic characteristics.}, language = {en} } @article{AkimbekovDigelZhubanova2014, author = {Akimbekov, N. Sh. and Digel, Ilya and Zhubanova, A. A.}, title = {Advantages of creation of e-books in training of specialists biologists and biotechnologists}, series = {KazNU Bulletin. Biology series.}, volume = {60}, journal = {KazNU Bulletin. Biology series.}, number = {1}, publisher = {Al-Farabi Kazakh National University}, address = {Almaty}, issn = {1563-0218}, pages = {249 -- 252}, year = {2014}, abstract = {The necessity of e-books as a primary of learning, its opportunities for realization of competence during training biologist and biotechnologist specialists are determined. Definitions and requirements to the e-books, its advantages in comparison with traditional textbooks, and the ways of creation of e-books in the SunRav BookEditor program are considered.}, language = {ru} } @article{MoseleyHalamekKrameretal.2014, author = {Moseley, Fiona and Halamek, Jan and Kramer, Friederike and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Katz, Evgeny}, title = {An enzyme-based reversible CNOT logic gate realized in a flow system}, series = {Analyst}, volume = {139}, journal = {Analyst}, number = {8}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1364-5528 (E-Journal) ; 0003-2654 (Print)}, doi = {10.1039/C4AN00133H}, pages = {1839 -- 1842}, year = {2014}, abstract = {An enzyme system organized in a flow device was used to mimic a reversible Controlled NOT (CNOT) gate with two input and two output signals. Reversible conversion of NAD⁺ and NADH cofactors was used to perform a XOR logic operation, while biocatalytic hydrolysis of p-nitrophenyl phosphate resulted in an Identity operation working in parallel. The first biomolecular realization of a CNOT gate is promising for integration into complex biomolecular networks and future biosensor/biomedical applications.}, language = {en} } @article{Dikta2014, author = {Dikta, Gerhard}, title = {Asymptotically efficient estimation under semi-parametric random censorship models}, series = {Journal of multivariate analysis}, volume = {124}, journal = {Journal of multivariate analysis}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1095-7243 (E-Journal); 0047-259X (Print)}, doi = {10.1016/j.jmva.2013.10.002}, pages = {10 -- 24}, year = {2014}, abstract = {We study the estimation of some linear functionals which are based on an unknown lifetime distribution. The observations are assumed to be generated under the semi-parametric random censorship model (SRCM), that is, a random censorship model where the conditional expectation of the censoring indicator given the observation belongs to a parametric family. Under this setup a semi-parametric estimator of the survival function was introduced by the author. If the parametric model assumption is correct, it is known that the estimated functional which is based on this semi-parametric estimator is asymptotically at least as efficient as the corresponding one which rests on the nonparametric Kaplan-Meier estimator. In this paper we show that the estimated functional which is based on this semi-parametric estimator is asymptotically efficient with respect to the class of all regular estimators under this semi-parametric model.}, language = {en} } @article{HuckPoghossianBaeckeretal.2014, author = {Huck, Christina and Poghossian, Arshak and B{\"a}cker, Matthias and Chaudhuri, S. and Zander, W. and Schubert, J. and Begoyan, V. K. and Buniatyan, V. V. and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Capacitively coupled electrolyte-conductivity sensor based on high-k material of barium strontium titanate}, series = {Sensors and actuators. B: Chemical}, journal = {Sensors and actuators. B: Chemical}, number = {198}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.02.103}, pages = {102 -- 109}, year = {2014}, language = {en} } @article{HuckPoghossianBaeckeretal.2014, author = {Huck, Christina and Poghossian, Arshak and B{\"a}cker, Matthias and Reisert, Steffen and Schubert, J. and Zander, W. and Begoyan, V. K. and Buniatyan, V. V. and Sch{\"o}ning, Michael Josef}, title = {Chemical sensors based on a high-k perovskite oxide of barium strontium titanate}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.258}, pages = {28 -- 31}, year = {2014}, abstract = {High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors for liquids. In this work, BST films have been applied as a sensitive transducer material for a label-free detection of adsorbed charged macromolecules (positively charged polyelectrolytes) and concentration of hydrogen peroxide vapor as well as protection insulator layer for a contactless electrolyte-conductivity sensor. The experimental results of characterization of individual sensors are presented. Special emphasis is devoted towards the development of a capacitively-coupled contactless electrolyte-conductivity sensor.}, language = {en} } @article{OberlaenderKirchnerBoyenetal.2014, author = {Oberl{\"a}nder, Jan and Kirchner, Patrick and Boyen, Hans-Gerd and Sch{\"o}ning, Michael Josef}, title = {Detection of hydrogen peroxide vapor by use of manganese(IV) oxide as catalyst for calorimetric gas sensors}, 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-Journal); 1862-6319 (E-Journal); 0031-8965 (Print); 1862-6300 (Print)}, doi = {10.1002/pssa.201330359}, pages = {1372 -- 1376}, year = {2014}, abstract = {In this work, the catalyst manganese(IV) oxide (MnO2), of calorimetric gas sensors (to monitor the sterilization agent vaporized hydrogen peroxide) has been investigated in more detail. Chemical analyses by means of X-ray-induced photoelectron spectroscopy have been performed to unravel the surface chemistry prior and after exposure to hydrogen peroxide vapor at elevated temperature, as applied in the sterilization processes of beverage cartons. The surface characterization reveals a change in oxidation states of the metal oxide catalyst after exposure to hydrogen peroxide. Additionally, a cleaning effect of the catalyst, which itself is attached to the sensor surface by means of a polymer interlayer, could be observed.}, language = {en} } @article{GuoMiyamotoWagneretal.2014, author = {Guo, Yuanyuan and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Device simulation of the light-addressable potentiometric sensor for the investigation of the spatial resolution}, series = {Sensors and actuators B: Chemical}, volume = {204}, journal = {Sensors and actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2014.08.016}, pages = {659 -- 665}, year = {2014}, abstract = {As a semiconductor-based electrochemical sensor, the light-addressable potentiometric sensor (LAPS) can realize two dimensional visualization of (bio-)chemical reactions at the sensor surface addressed by localized illumination. Thanks to this imaging capability, various applications in biochemical and biomedical fields are expected, for which the spatial resolution is critically significant. In this study, therefore, the spatial resolution of the LAPS was investigated in detail based on the device simulation. By calculating the spatiotemporal change of the distributions of electrons and holes inside the semiconductor layer in response to a modulated illumination, the photocurrent response as well as the spatial resolution was obtained as a function of various parameters such as the thickness of the Si substrate, the doping concentration, the wavelength and the intensity of illumination. The simulation results verified that both thinning the semiconductor substrate and increasing the doping concentration could improve the spatial resolution, which were in good agreement with known experimental results and theoretical analysis. More importantly, new findings of interests were also obtained. As for the dependence on the wavelength of illumination, it was found that the known dependence was not always the case. When the Si substrate was thick, a longer wavelength resulted in a higher spatial resolution which was known by experiments. When the Si substrate was thin, however, a longer wavelength of light resulted in a lower spatial resolution. This finding was explained as an effect of raised concentration of carriers, which reduced the thickness of the space charge region. The device simulation was found to be helpful to understand the relationship between the spatial resolution and device parameters, to understand the physics behind it, and to optimize the device structure and measurement conditions for realizing higher performance of chemical imaging systems.}, language = {en} } @article{GuoSekiMiyamotoetal.2014, author = {Guo, Yuanyuan and Seki, Kosuke and Miyamoto, Ko-ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Device simulation of the light-addressable potentiometric sensor with a novel photoexcitation method for a higher spatial resolution}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.369}, pages = {456 -- 459}, year = {2014}, abstract = {A novel photoexcitation method for the light-addressable potentiometric sensor (LAPS) realized a higher spatial resolution of chemical imaging. In this method, a modulated light probe, which generates the alternating photocurrent signal, is surrounded by a ring of constant light, which suppresses the lateral diffusion of photocarriers by enhancing recombination. A device simulation verified that a higher spatial resolution could be obtained by adjusting the gap between the modulated and constant light. It was also found that a higher intensity and a longer wavelength of constant light was more effective. However, there exists a tradeoff between the spatial resolution and the amplitude of the photocurrent, and thus, the signal-to-noise ratio. A tilted incidence of constant light was applied, which could achieve even higher resolution with a smaller loss of photocurrent.}, 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{MiyamotoSekiWagneretal.2014, author = {Miyamoto, K. and Seki, K. and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, T.}, title = {Enhancement of the spatial resolution of the chemical imaging sensor by a hybrid fiber-optic illumination}, series = {Procedia Engineering}, volume = {87}, journal = {Procedia Engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2014.11.563}, pages = {612 -- 615}, year = {2014}, abstract = {The chemical imaging sensor, which is based on the principle of the light-addressable potentiometric sensor (LAPS), is a powerful tool to visualize the spatial distribution of chemical species on the sensor surface. The spatial resolution of this sensor depends on the diffusion of photocarriers excited by a modulated light. In this study, a novel hybrid fiber-optic illumination was developed to enhance the spatial resolution. It consists of a modulated light probe to generate a photocurrent signal and a ring of constant light, which suppresses the lateral diffusion of minority carriers excited by the modulated light. It is demonstrated that the spatial resolution was improved from 92 μm to 68 μm.}, 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{BandodkarMolinnusMirzaetal.2014, author = {Bandodkar, Amay J. and Molinnus, Denise and Mirza, Omar and Guinovart, Tomas and Windmiller, Joshua R. and Valdes-Ramirez, Gabriela and Andrade, Francisco J. and Sch{\"o}ning, Michael Josef and Wang, Joseph}, title = {Epidermal tattoo potentiometric sodium sensors with wireless signal transduction for continuous non-invasive sweat monitoring}, series = {Biosensors and bioelectronics}, volume = {54}, journal = {Biosensors and bioelectronics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4235 (E-Journal); 0956-5663 (Print)}, doi = {10.1016/j.bios.2013.11.039}, pages = {603 -- 609}, year = {2014}, abstract = {This article describes the fabrication, characterization and application of an epidermal temporary-transfer tattoo-based potentiometric sensor, coupled with a miniaturized wearable wireless transceiver, for real-time monitoring of sodium in the human perspiration. Sodium excreted during perspiration is an excellent marker for electrolyte imbalance and provides valuable information regarding an individual's physical and mental wellbeing. The realization of the new skin-worn non-invasive tattoo-like sensing device has been realized by amalgamating several state-of-the-art thick film, laser printing, solid-state potentiometry, fluidics and wireless technologies. The resulting tattoo-based potentiometric sodium sensor displays a rapid near-Nernstian response with negligible carryover effects, and good resiliency against various mechanical deformations experienced by the human epidermis. On-body testing of the tattoo sensor coupled to a wireless transceiver during exercise activity demonstrated its ability to continuously monitor sweat sodium dynamics. The real-time sweat sodium concentration was transmitted wirelessly via a body-worn transceiver from the sodium tattoo sensor to a notebook while the subjects perspired on a stationary cycle. The favorable analytical performance along with the wearable nature of the wireless transceiver makes the new epidermal potentiometric sensing system attractive for continuous monitoring the sodium dynamics in human perspiration during diverse activities relevant to the healthcare, fitness, military, healthcare and skin-care domains.}, language = {en} } @article{LehnertzAnsmannBialonskietal.2014, author = {Lehnertz, Klaus and Ansmann, Gerrit and Bialonski, Stephan and Dickten, Henning and Geier, Christian and Porz, Stephan}, title = {Evolving networks in the human epileptic brain}, series = {Physica D: Nonlinear Phenomena}, volume = {267}, journal = {Physica D: Nonlinear Phenomena}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0167-2789}, doi = {10.1016/j.physd.2013.06.009}, pages = {7 -- 15}, year = {2014}, abstract = {Network theory provides novel concepts that promise an improved characterization of interacting dynamical systems. Within this framework, evolving networks can be considered as being composed of nodes, representing systems, and of time-varying edges, representing interactions between these systems. This approach is highly attractive to further our understanding of the physiological and pathophysiological dynamics in human brain networks. Indeed, there is growing evidence that the epileptic process can be regarded as a large-scale network phenomenon. We here review methodologies for inferring networks from empirical time series and for a characterization of these evolving networks. We summarize recent findings derived from studies that investigate human epileptic brain networks evolving on timescales ranging from few seconds to weeks. We point to possible pitfalls and open issues, and discuss future perspectives.}, language = {en} } @article{PhamStaat2014, author = {Pham, Phu Tinh and Staat, Manfred}, title = {FEM-based shakedown analysis of hardening structures}, series = {Asia Pacific journal on computational engineering}, journal = {Asia Pacific journal on computational engineering}, number = {1}, publisher = {SpringerOpen}, address = {Berlin}, issn = {2196-1166 (E-Journal)}, doi = {10.1186/2196-1166-1-4}, pages = {Article No. 4}, year = {2014}, abstract = {This paper develops a new finite element method (FEM)-based upper bound algorithm for limit and shakedown analysis of hardening structures by a direct plasticity method. The hardening model is a simple two-surface model of plasticity with a fixed bounding surface. The initial yield surface can translate inside the bounding surface, and it is bounded by one of the two equivalent conditions: (1) it always stays inside the bounding surface or (2) its centre cannot move outside the back-stress surface. The algorithm gives an effective tool to analyze the problems with a very high number of degree of freedom. Our numerical results are very close to the analytical solutions and numerical solutions in literature.}, language = {en} } @article{Stulpe2014, author = {Stulpe, Werner}, title = {From the attempt of certain classical reformulations of quantum mechanics to quasi-probability representations}, series = {Journal of Mathematical Physics}, volume = {55}, journal = {Journal of Mathematical Physics}, number = {1}, publisher = {AIP Publishing}, address = {College Park, Md.}, issn = {222-488}, doi = {10.1063/1.4861939}, pages = {Artikel 012109}, year = {2014}, abstract = {The concept of an injective affine embedding of the quantum states into a set of classical states, i.e., into the set of the probability measures on some measurable space, as well as its relation to statistically complete observables is revisited, and its limitation in view of a classical reformulation of the statistical scheme of quantum mechanics is discussed. In particular, on the basis of a theorem concerning a non-denseness property of a set of coexistent effects, it is shown that an injective classical embedding of the quantum states cannot be supplemented by an at least approximate classical description of the quantum mechanical effects. As an alternative approach, the concept of quasi-probability representations of quantum mechanics is considered.}, language = {en} } @article{MiyamotoItabashiWagneretal.2014, author = {Miyamoto, Ko-ichiro and Itabashi, Akinori and Wagner, Torsten and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {High-speed chemical imaging inside a microfluidic channel}, series = {Sensors and actuators. B: Chemical}, volume = {194}, journal = {Sensors and actuators. B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-3077 (E-Journal); 0925-4005 (Print)}, doi = {10.1016/j.snb.2013.12.090}, pages = {521 -- 527}, year = {2014}, abstract = {In this study, a high-speed chemical imaging system was developed for visualization of the interior of a microfluidic channel. A microfluidic channel was constructed on the sensor surface of the light-addressable potentiometric sensor (LAPS), on which the ion concentrations could be measured in parallel at up to 64 points illuminated by optical fibers. The temporal change of pH distribution inside the microfluidic channel was recorded at a maximum rate of 100 frames per second (fps). The high frame rate allowed visualization of moving interfaces and plugs in the channel even at a flow velocity of 111 mm/s, which suggests the feasibility of plug-based microfluidic devices for flow-injection analysis (FIA).}, language = {en} } @article{RiedelKartchemnikSchoeningetal.2014, author = {Riedel, Marc and Kartchemnik, Julia and Sch{\"o}ning, Michael Josef and Lisdat, Fred}, title = {Impedimetric DNA detection - steps forward to sensorial application}, series = {Analytical chemistry}, volume = {86 (2014)}, journal = {Analytical chemistry}, number = {15}, publisher = {ACS Publications}, address = {Columbus}, issn = {1520-6882 (E-Journal); 0003-2700 (Print); 0096-4484 (Print)}, doi = {10.1021/ac501800q}, pages = {7867 -- 7874}, year = {2014}, abstract = {This study describes a label-free impedimetric sensor based on short ssDNA recognition elements for the detection of hybridization events. We concentrate on the elucidation of the influence of target length and recognition sequence position on the sensorial performance. The impedimetric measurements are performed in the presence of the redox system ferri-/ferrocyanide and show an increase in charge transfer resistance upon hybridization of ssDNA to the sensor surface. Investigations on the impedimetric signal stability demonstrate a clear influence of the buffers used during the sensor preparation and the choice of the passivating mercaptoalcanol compound. A stable sensor system has been developed, enabling a reproducible detection of 25mer target DNA in the low nanomolar range. After hybridization, a sensor regeneration can be reached with deionized water by adjustment of effective convection conditions, ensuring a sensor reusability. By investigations of longer targets with overhangs exposed to the solution, we can demonstrate applicability of the impedimetric detection for longer ssDNA. However, a decreasing charge transfer resistance change (ΔRct) is found by extending the overhang. As a strategy to increase the impedance change for longer target strands, the position of the recognition sequence can be designed in a way that a small overhang is exposed to the electrode surface. This is found to result in an increase in the relative Rct change. These results suggest that DNA and consequently negative charge near the electrode possess a larger impact on the impedimetric signal than DNA further away.}, language = {en} } @article{SiqueiraMolinnusBegingetal.2014, author = {Siqueira, Jose R. and Molinnus, Denise and Beging, Stefan and Sch{\"o}ning, Michael Josef}, title = {Incorporating a hybrid urease-carbon nanotubes sensitive nanofilm on capacitive field-effect sensors for urea detection}, series = {Analytical chemistry}, volume = {86}, journal = {Analytical chemistry}, number = {11}, publisher = {ACS Publications}, address = {Columbus}, issn = {1520-6882 (E-Journal); 0003-2700 (Print); 0096-4484 (Print)}, doi = {10.1021/ac500458s}, pages = {5370 -- 5375}, year = {2014}, abstract = {The ideal combination among biomolecules and nanomaterials is the key for reaching biosensing units with high sensitivity. The challenge, however, is to find out a stable and sensitive film architecture that can be incorporated on the sensor's surface. In this paper, we report on the benefits of incorporating a layer-by-layer (LbL) nanofilm of polyamidoamine (PAMAM) dendrimer and carbon nanotubes (CNTs) on capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensors for detecting urea. Three sensor arrangements were studied in order to investigate the adequate film architecture, involving the LbL film with the enzyme urease: (i) urease immobilized directly onto a bare EIS [EIS-urease] sensor; (ii) urease atop the LbL film over the EIS [EIS-(PAMAM/CNT)-urease] sensor; and (iii) urease sandwiched between the LbL film and another CNT layer [EIS-(PAMAM/CNT)-urease-CNT]. The surface morphology of all three urea-based EIS biosensors was investigated by atomic force microscopy (AFM), while the biosensing abilities were studied by means of capacitance-voltage (C/V) and dynamic constant-capacitance (ConCap) measureaments at urea concentrations ranging from 0.1 mM to 100 mM. The EIS-urease and EIS-(PAMAM/CNT)-urease sensors showed similar sensitivity (∼18 mV/decade) and a nonregular signal behavior as the urea concentration increased. On the other hand, the EIS-(PAMAM/CNT)-urease-CNT sensor exhibited a superior output signal performance and higher sensitivity of about 33 mV/decade. The presence of the additional CNT layer was decisive to achieve a urea based EIS sensor with enhanced properties. Such sensitive architecture demonstrates that the incorporation of an adequate hybrid enzyme-nanofilm as sensing unit opens new prospects for biosensing applications using the field-effect sensor platform.}, language = {en} }