Refine
Year of publication
Document Type
- Article (160)
- Conference Proceeding (20)
- Part of a Book (9)
- Book (1)
Language
- English (190) (remove)
Keywords
- Field-effect sensor (3)
- Label-free detection (3)
- capacitive field-effect sensor (3)
- field-effect sensor (3)
- tobacco mosaic virus (TMV) (3)
- Biosensor (2)
- Capacitive field-effect sensor (2)
- LAPS (2)
- Tobacco mosaic virus (TMV) (2)
- gold nanoparticles (2)
- (Bio)degradation (1)
- Biomolecular logic gate (1)
- Biosensorik (1)
- CNOT (1)
- Capacitive field-effect (1)
- Capacitive model (1)
- Chemical imaging (1)
- Coat protein (1)
- C–V method (1)
- DNA (1)
- DNA biosensor (1)
- DNA hybridization (1)
- Electrolyte–insulator–semiconductor (1)
- Enzyme biosensor (1)
- Enzyme coverage (1)
- Enzyme logic gate (1)
- Enzyme nanocarrier (1)
- Field effect (1)
- Field-effect biosensor (1)
- Field-effect device (1)
- Glucose biosensor (1)
- Glucose oxidase (1)
- Gold nanoparticle (1)
- Gold nanoparticles (1)
- ISFET (1)
- Impedance spectroscopy (1)
- Layer-by-layer adsorption (1)
- Light-addressable potentiometric sensor (1)
- Multianalyte detection (1)
- Multicell (1)
- Multiplexing (1)
- Nanostructuring (1)
- Penicillin (1)
- Plant virus (1)
- Poly(allylamine hydrochloride) (1)
- Poly(d,l-lacticacid) (1)
- Potentiometry (1)
- Real-time monitoring (1)
- TMV adsorption (1)
- Ta₂O₅ gate (1)
- Tobacco mosaic virus (1)
- Wafer (1)
- XOR (1)
- Zeta potential (1)
- acetoin (1)
- aminooctanethiol (1)
- atomic layer deposition (1)
- barium strontium titanate (1)
- bi-enzyme biosensor (1)
- biosensor (1)
- capacitive EIS sensor (1)
- capacitive field-effect biosensor (1)
- capacitive field-effect sensors (1)
- capacitive model (1)
- capillary micro-droplet cell (1)
- contactless conductivity sensor (1)
- control gate (1)
- detection of charged macromolecules (1)
- electrolyte-insulator-semiconductor capacitors (1)
- enzymatic (bio)degradation (1)
- enzyme cascade (1)
- enzyme immobilization (1)
- enzyme-logic gate (1)
- equivalent circuit (1)
- glucose oxidase (GOx) (1)
- high-k material (1)
- horseradish peroxidase (HRP) (1)
- hydrogen peroxide (1)
- impedance spectroscopy (1)
- in-situ monitoring (1)
- lable-free detection (1)
- layer expansion (1)
- multi-functional material (1)
- multianalyte detection (1)
- nanoparticle coverage (1)
- on-chip integrated addressable EISCAP sensors (1)
- pH sensors (1)
- pattern-size reduction (1)
- penicillinase (1)
- plant virus detection (1)
- poly(d, l-lactic acid) (1)
- polystyrene sulfonate (1)
- self-aligned patterning (1)
- turnip vein clearing virus (TVCV) (1)
- ultrathin gate insulators (1)
- urease (1)
- wafer-level testing (1)
It is well known that biochemical and biotechnological processes are strongly dependent and affected by a variety of physico-chemical parameters such as pH value, temperature, pressure and electrolyte conductivity. Therefore, these quantities have to be monitored or controlled in order to guarantee a stable process operation, optimization and high yield. In this work, a sensor chip for the multiparameter detection of three physico-chemical parameters such as electrolyte conductivity, pH and temperature is realized using barium strontium titanate (BST) as multipurpose material. The chip integrates a capacitively coupled four-electrode electrolyte-conductivity sensor, a capacitive field-effect pH sensor and a thin-film Pt-temperature sensor. Due to the multifunctional properties of BST, it is utilized as final outermost coating layer of the processed sensor chip and serves as passivation and protection layer as well as pH-sensitive transducer material at the same time. The results of testing of the individual sensors of the developed multiparameter sensor chip are presented. In addition, a quasi-simultaneous multiparameter characterization of the sensor chip in buffer solutions with different pH value and electrolyte conductivity is performed. To study the sensor behavior and the suitability of BST as multifunctional material under harsh environmental conditions, the sensor chip was exemplarily tested in a biogas digestate.
High-k perovskite oxide of barium strontium titanate (BST) represents a very attractive multi-functional transducer material for the development of (bio-)chemical sensors. In this work, a Si-based sensor chip containing Pt interdigitated electrodes covered with a thin BST layer (485 nm) has been developed for multi-parameter chemical sensing. The chip has been applied for the contactless measurement of the electrolyte conductivity, the detection of adsorbed charged macromolecules (positively charged polyelectrolytes of polyethylenimine) and the concentration of hydrogen peroxide (H2O2) vapor. The experimental results of functional testing of individual sensors are presented. The mechanism of the BST sensitivity to charged polyelectrolytes and H2O2 vapor has been proposed and discussed.
Multi-parameter detection for supporting monitoring and control of biogas processes in agriculture
(2014)
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.
Miniaturized electrolyte–insulator–semiconductor capacitors (EISCAPs) with ultrathin gate insulators have been studied in terms of their pH-sensitive sensor characteristics: three different EISCAP systems consisting of Al–p-Si–Ta2O5(5 nm), Al–p-Si–Si3N4(1 or 2 nm)–Ta2O5 (5 nm), and Al–p-Si–SiO2(3.6 nm)–Ta2O5(5 nm) layer structures are characterized in buffer solution with different pH values by means of capacitance–voltage and constant capacitance method. The SiO2 and Si3N4 gate insulators are deposited by rapid thermal oxidation and rapid thermal nitridation, respectively, whereas the Ta2O5 film is prepared by atomic layer deposition. All EISCAP systems have a clear pH response, favoring the stacked gate insulators SiO2–Ta2O5 when considering the overall sensor characteristics, while the Si3N4(1 nm)–Ta2O5 stack delivers the largest accumulation capacitance (due to the lower equivalent oxide thickness) and a higher steepness in the slope of the capacitance–voltage curve among the studied stacked gate insulator systems.
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.