@inproceedings{MirmohseniRostamizadeh2006, author = {Mirmohseni, Abdolreza and Rostamizadeh, Kobra}, title = {Quartz crystal nanobalance in conjunction with principal component analysis for identification of volatile organic compounds}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1434}, year = {2006}, abstract = {Quartz crystal nanobalance (QCN) sensors are considered as powerful masssensitive sensors to determine materials in the sub-nanogram level. In this study, a single piezoelectric quartz crystal nanobalance modified with polystyrene was employed to detect benzene, toluene, ethylbenzene and xylene (BTEX compounds). The frequency shift of the QCN sensor was found to be linear against the BTEX compound concentrations in the range about 1-45 mg l-1. The correlation coefficients for benzene, toluene, ethylbenzene, and xylene were 0.991, 0.9977, 0.9946 and 0.9971, respectively. The principal component analysis was also utilized to process the frequency response data of the single piezoelectric crystal at different times, considering to the different adsorption-desorption dynamics of BTEX compounds. Using principal component analysis, it was found that over 90\% of the data variance could still be explained by use of two principal components (PC1 and PC2). Subsequently, the successful identification of benzene and toluene was possible through the principal component analysis of the transient responses of the polystyrene modified QCN sensor. The results showed that the polystyrene-modified QCN had favorable identification and quantification performances for the BTEX compounds.}, subject = {Biosensor}, language = {en} } @inproceedings{KreutzLoergenGraeweetal.2006, author = {Kreutz, Christian and L{\"o}rgen, J{\"u}rgen and Graewe, Boris and Bargon, Joachim and Yoshida, Mayumi and Freso, Zachary M. and Fr{\`e}chet, Jean M. J.}, title = {High frequency quartz micro balances: a promising path to enhanced sensitivity of gravimetric sensors}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1445}, year = {2006}, abstract = {An array of 50 MHz quartz microbalances (QMBs) coated with a dendronized polymer was used to detect small amounts of volatile organic compounds (VOCs) in the gas phase. The results were compared to those obtained with the commonly used 10 MHz QMBs. The 50 MHz QMBs proved to be a powerful tool for the detection of VOCs in the gas phase; therefore, they represent a promising alternative to the much more delicate surface acoustic wave devices (SAWs).}, subject = {Biosensor}, language = {en} } @inproceedings{RabnerShacham2006, author = {Rabner, Arthur and Shacham, Yosi}, title = {A concept for a sensitive micro total analysis system for high throughput fluorescence imaging}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1456}, year = {2006}, abstract = {This paper discusses possible methods for on-chip fluorescent imaging for integrated bio-sensors. The integration of optical and electro-optical accessories, according to suggested methods, can improve the performance of fluorescence imaging. It can boost the signal to background ratio by a few orders of magnitudes in comparison to conventional discrete setups. The methods that are present in this paper are oriented towards building reproducible arrays for high-throughput micro total analysis systems (µTAS). The first method relates to side illumination of the fluorescent material placed into microcompartments of the lab-on-chip. Its significance is in high utilization of excitation energy for low concentration of fluorescent material. The utilization of a transparent µLED chip, for the second method, allows the placement of the excitation light sources on the same optical axis with emission detector, such that the excitation and emission rays are directed controversly. The third method presents a spatial filtering of the excitation background.}, subject = {Biosensor}, language = {en} } @inproceedings{FoersterStockMontanarietal.2006, author = {F{\"o}rster, Arnold and Stock, J{\"u}rgen and Montanari, Simone and Lepsa, Mihail Ion and L{\"u}th, Hans}, title = {Fabrication and characterisation of GaAs Gunn Diode Chips for applications at 77 GHz in automotive industry}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1462}, year = {2006}, abstract = {GaAs-based Gunn diodes with graded AlGaAs hot electron injector heterostructures have been developed under the special needs in automotive applications. The fabrication of the Gunn diode chips was based on total substrate removal and processing of integrated Au heat sinks. Especially, the thermal and RF behavior of the diodes have been analyzed by DC, impedance and S-parameter measurements. The electrical investigations have revealed the functionality of the hot electron injector. An optimized layer structure could fulfill the requirements in adaptive cruise control (ACC) systems at 77 GHz with typical output power between 50 and 90 mW.}, subject = {Biosensor}, language = {en} } @inproceedings{PlatenPoghossianSchoening2006, author = {Platen, Johannes and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Microstructured Nanostructures - nanostructuring by means of conventional photolithography and layer-expansion technique}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1477}, year = {2006}, abstract = {A new and simple method for nanostructuring using conventional photolithography and layer expansion or pattern-size reduction technique is presented, which can further be applied for the fabrication of different nanostructures and nano-devices. The method is based on the conversion of a photolithographically patterned metal layer to a metal-oxide mask with improved pattern-size resolution using thermal oxidation. With this technique, the pattern size can be scaled down to several nanometer dimensions. The proposed method is experimentally demonstrated by preparing nanostructures with different configurations and layouts, like circles, rectangles, trapezoids, "fluidic-channel"-, "cantilever"- and meander-type structures.}, subject = {Biosensor}, language = {en} } @inproceedings{PijanowskaRemiszewskaPederzollietal.2006, author = {Pijanowska, Dorota G. and Remiszewska, Elzbieta and Pederzolli, Cecilia and Lunelli, Lorenzo and Vendano, Michele and Canteri, Roberto and Dudzinski, Konrad and Kruk, Jerzy and Torbicz, Wladyslaw}, title = {Surface modification for microreactor fabrication}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1480}, year = {2006}, abstract = {In this paper, methods of surface modification of different supports, i.e. glass and polymeric beads for enzyme immobilisation are described. The developed method of enzyme immobilisation is based on Schiff's base formation between the amino groups on the enzyme surface and the aldehyde groups on the chemically modified surface of the supports. The surface of silicon modified by APTS and GOPS with immobilised enzyme was characterised by atomic force microscopy (AFM), time-of-flight secondary ion mass spectroscopy (ToF-SIMS) and infrared spectroscopy (FTIR). The supports with immobilised enzyme (urease) were also tested in combination with microreactors fabricated in silicon and Perspex, operating in a flow-through system. For microreactors filled with urease immobilised on glass beads (Sigma) and on polymeric beads (PAN), a very high and stable signal (pH change) was obtained. The developed method of urease immobilisation can be stated to be very effective.}, subject = {Biosensor}, language = {en} } @inproceedings{BukhariYang2006, author = {Bukhari, Syed Faisal Ahmed and Yang, Wuqiang}, title = {Multi-interface level sensors and new development in monitoring and control of oil separators}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1498}, year = {2006}, abstract = {In the oil industry, huge saving may be made if suitable multi-interface level measurement systems are employed for effectively monitoring crude oil separators and efficient control of their operation. A number of techniques, e.g. externally mounted displacers, differential pressure transmitters and capacitance rod devices, have been developed to measure the separation process with gas, oil, water and other components. Because of the unavailability of suitable multi-interface level measurement systems, oil separators are currently operated by the trial-and-error approach. In this paper some conventional techniques, which have been used for level measurement in industry, and new development are discussed.}, subject = {Biosensor}, language = {en} } @inproceedings{TymeckiGlabKoncki2006, author = {Tymecki, Lukasz and Glab, Stanislaw and Koncki, Robert}, title = {Miniaturized, planar ion-selective electrodes fabricated by means of thick-film technology}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1506}, year = {2006}, abstract = {Various planar technologies are employed for developing solid-state sensors having low cost, small size and high reproducibility; thin- and thick-film technologies are most suitable for such productions. Screen-printing is especially suitable due to its simplicity, low-cost, high reproducibility and efficiency in large-scale production. This technology enables the deposition of a thick layer and allows precise pattern control. Moreover, this is a highly economic technology, saving large amounts of the used inks. In the course of repetitions of the film-deposition procedure there is no waste of material due to additivity of this thick-film technology. Finally, the thick films can be easily and quickly deposited on inexpensive substrates. In this contribution, thick-film ion-selective electrodes based on ionophores as well as crystalline ion-selective materials dedicated for potentiometric measurements are demonstrated. Analytical parameters of these sensors are comparable with those reported for conventional potentiometric electrodes. All mentioned thick-film strip electrodes have been totally fabricated in only one, fully automated thickfilm technology, without any additional manual, chemical or electrochemical steps. In all cases simple, inexpensive, commercially available materials, i.e. flexible, plastic substrates and easily cured polymer-based pastes were used.}, subject = {Biosensor}, language = {en} } @inproceedings{SpannhakeSchulzHelwigetal.2006, author = {Spannhake, Jan and Schulz, Olaf and Helwig, Andreas and Krenkow, Angelika and M{\"u}ller, Gerhard and Doll, Theodor}, title = {High-temperature MEMS heater platforms: long-term performance of metal and semiconductor heater materials}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1513}, year = {2006}, abstract = {Micromachined thermal heater platforms offer low electrical power consumption and high modulation speed, i.e. properties which are advantageous for realizing nondispersive infrared (NDIR) gas- and liquid monitoring systems. In this paper, we report on investigations on silicon-on-insulator (SOI) based infrared (IR) emitter devices heated by employing different kinds of metallic and semiconductor heater materials. Our results clearly reveal the superior high-temperature performance of semiconductor over metallic heater materials. Long-term stable emitter operation in the vicinity of 1300 K could be attained using heavily antimony-doped tin dioxide (SnO2:Sb) heater elements.}, subject = {Biosensor}, language = {en} } @inproceedings{KatzWillner2006, author = {Katz, Eugenii and Willner, Itamar}, title = {Magneto-controlled quantized electron transfer to surface-confined redox units and metal nanoparticles}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-1528}, year = {2006}, abstract = {Hydrophobic magnetic nanoparticles (NPs) consisting of undecanoate-capped magnetite (Fe3O4, average diameter ca. 5 nm) are used to control quantized electron transfer to surface-confined redox units and metal NPs. A two-phase system consisting of an aqueous electrolyte solution and a toluene phase that includes the suspended undecanoatecapped magnetic NPs is used to control the interfacial properties of the electrode surface. The attracted magnetic NPs form a hydrophobic layer on the electrode surface resulting in the change of the mechanisms of the surface-confined electrochemical processes. A quinone-monolayer modified Au electrode demonstrates an aqueous-type of the electrochemical process (2e-+2H+ redox mechanism) for the quinone units in the absence of the hydrophobic magnetic NPs, while the attraction of the magnetic NPs to the surface results in the stepwise single-electron transfer mechanism characteristic of a dry nonaqueous medium. Also, the attraction of the hydrophobic magnetic NPs to the Au electrode surface modified with Au NPs (ca. 1.4 nm) yields a microenvironment with a low dielectric constant that results in the single-electron quantum charging of the Au NPs.}, subject = {Biosensor}, language = {en} }