Refine
Year of publication
Document Type
- Article (519)
- Conference Proceeding (48)
- Part of a Book (10)
- Book (2)
- Other (2)
- Patent (1)
- Report (1)
Has Fulltext
- no (583) (remove)
Keywords
- LAPS (4)
- Field-effect sensor (3)
- Light-addressable potentiometric sensor (3)
- hydrogen peroxide (3)
- Bacillus atrophaeus (2)
- Raman spectroscopy (2)
- field-effect sensor (2)
- tobacco mosaic virus (TMV) (2)
- (Bio)degradation (1)
- Bacillus atrophaeus spores (1)
- Biomolecular logic gate (1)
- CNOT (1)
- Calorimetric gas sensor (1)
- Capacitive field-effect (1)
- Capacitive model (1)
- Chemical images (1)
- Chemical imaging (1)
- Chemical imaging sensor (1)
- Chemical sensor (1)
- Coat protein (1)
- C–V method (1)
- DNA (1)
- DNA biosensor (1)
- DNA hybridization (1)
- DPA (dipicolinic acid) (1)
- Dehydrogenase (1)
- Diaphorase (1)
- EIS capacitive sensor (1)
- Electrolyte–insulator–semiconductor (1)
- Enzymatic biosensor (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)
- Hydrogen peroxide (1)
- Impedance spectroscopy (1)
- Label-free detection (1)
- Layer-by-layer adsorption (1)
- LbL films (1)
- Light-addressable Potentiometric Sensor (1)
- MOS (1)
- Multianalyte detection (1)
- Negative impedance convertor (1)
- O2 plasma (1)
- Organic light-emitting diode display (1)
- Penicillin (1)
- Poly(allylamine hydrochloride) (1)
- Poly(d,l-lacticacid) (1)
- Polyimide (1)
- Potentiometry (1)
- Real-time monitoring (1)
- Resonance-mode measurement (1)
- Simultaneous determination (1)
- Sn₃O₄ (1)
- Sterilisation process (1)
- TMV adsorption (1)
- Ta₂O₅ gate (1)
- Tobacco mosaic virus (1)
- Tobacco mosaic virus (TMV) (1)
- XOR (1)
- acetoin (1)
- annealing (1)
- artificial olfactory image (1)
- barium strontium titanate (1)
- biosensor (1)
- biosensors (1)
- calorimetric gas sensor (1)
- calorimetric gas sensor;hydrogen peroxide;wireless sensor system (1)
- capacitive field-effect biosensor (1)
- capacitive field-effect sensor (1)
- catalytic metal (1)
- chemical sensor (1)
- contactless conductivity sensor (1)
- electrolyte-insulator semiconductor sensor (EIS) (1)
- electronic nose (1)
- endospores (1)
- enzymatic (bio)degradation (1)
- enzyme cascade (1)
- enzyme immobilization (1)
- field-effect structure (1)
- gas sensor (1)
- glucose oxidase (GOx) (1)
- heavy metals (1)
- high-k material (1)
- horseradish peroxidase (HRP) (1)
- hydroxylation (1)
- immobilization (1)
- impedance spectroscopy (1)
- in-situ monitoring (1)
- lable-free detection (1)
- light-addressable potentiometric sensor (1)
- light-addressing technologies (1)
- metal-oxide-semiconductor structure (1)
- multi-functional material (1)
- nanobelts (1)
- novel photoexcitation method (1)
- optical sensor setup (1)
- optical spore trapping (1)
- optical trapping (1)
- organosilanes (1)
- plant virus detection (1)
- plug-based microfluidic device (1)
- poly(d, l-lactic acid) (1)
- scanned light pulse technique (1)
- silanization (1)
- spatial resolution (1)
- sterilisation (1)
- sterilization (1)
- sterilization conditions (1)
- surface functionalization (1)
- temperature (1)
- tilted constant illumination (1)
- turnip vein clearing virus (TVCV) (1)
- visualization (1)
Institute
- Fachbereich Medizintechnik und Technomathematik (583) (remove)
In this work, a cell-based biosensor to evaluate the sterilization efficacy of hydrogen peroxide vapor sterilization processes is characterized. The transducer of the biosensor is based on interdigitated gold electrodes fabricated on an inert glass substrate. Impedance spectroscopy is applied to evaluate the sensor behavior and the alteration of test microorganisms due to the sterilization process. These alterations are related to changes in relative permittivity and electrical conductivity of the bacterial spores. Sensor measurements are conducted with and without bacterial spores (Bacillus atrophaeus), as well as after an industrial sterilization protocol. Equivalent two-dimensional numerical models based on finite element method of the periodic finger structures of the interdigitated gold electrodes are designed and validated using COMSOL® Multiphysics software by the application of known dielectric properties. The validated models are used to compute the electrical properties at different sensor states (blank, loaded with spores, and after sterilization). As a final result, we will derive and tabulate the frequency-dependent electrical parameters of the spore layer using a novel model that combines experimental data with numerical optimization techniques.
A new microfluidic assembly method for semiconductor-based biosensors using 3D-printing technologies was proposed for a rapid and cost-efficient design of new sensor systems. The microfluidic unit is designed and printed by a 3D-printer in just a few hours and assembled on a light-addressable potentiometric sensor (LAPS) chip using a photo resin. The cell growth curves obtained from culturing cells within microfluidics-based LAPS systems were compared with cell growth curves in cell culture flasks to examine biocompatibility of the 3D-printed chips. Furthermore, an optimal cell culturing within microfluidics-based LAPS chips was achieved by adjusting the fetal calf serum concentrations of the cell culture medium, an important factor for the cell proliferation.
Immunosorbent turnip vein clearing virus (TVCV) particles displaying the IgG-binding domains D and E of Staphylococcus aureus protein A (PA) on every coat protein (CP) subunit (TVCVPA) were purified from plants via optimized and new protocols. The latter used polyethylene glycol (PEG) raw precipitates, from which virions were selectively re-solubilized in reverse PEG concentration gradients. This procedure improved the integrity of both TVCVPA and the wild-type subgroup 3 tobamovirus. TVCVPA could be loaded with more than 500 IgGs per virion, which mediated the immunocapture of fluorescent dyes, GFP, and active enzymes. Bi-enzyme ensembles of cooperating glucose oxidase and horseradish peroxidase were tethered together on the TVCVPA carriers via a single antibody type, with one enzyme conjugated chemically to its Fc region, and the other one bound as a target, yielding synthetic multi-enzyme complexes. In microtiter plates, the TVCVPA-displayed sugar-sensing system possessed a considerably increased reusability upon repeated testing, compared to the IgG-bound enzyme pair in the absence of the virus. A high coverage of the viral adapters was also achieved on Ta2O5 sensor chip surfaces coated with a polyelectrolyte interlayer, as a prerequisite for durable TVCVPA-assisted electrochemical biosensing via modularly IgG-assembled sensor enzymes.
A physically coupled finite element method (FEM) model is developed to study the response behavior of a calorimetric gas sensor. The modeled sensor serves as a monitoring device of the concentration of gaseous hydrogen peroxide (H2 O2) in a high temperature mixture stream in aseptic sterilization processes. The principle of operation of a calorimetric H2 O2 sensor is analyzed and the results of the numerical model have been validated by using previously published sensor experiments. The deviation in the results between the FEM model and experimental data are presented and discussed.
A field-effect biosensor employing tobacco mosaic virus (TMV) particles as scaffolds for enzyme immobilization is presented. Nanotubular TMV scaffolds allow a dense immobilization of precisely positioned enzymes with retained activity. To demonstrate feasibility of this new strategy, a penicillin sensor has been developed by coupling a penicillinase with virus particles as a model system. The developed field-effect penicillin biosensor consists of an Al-p-Si-SiO₂-Ta₂O₅-TMV structure and has been electrochemically characterized in buffer solutions containing different concentrations of penicillin G. In addition, the morphology of the biosensor surface with virus particles was characterized by scanning electron microscopy and atomic force microscopy methods. The sensors possessed a high penicillin sensitivity of ~ 92 mV/dec in a nearly-linear range from 0.1 mM to 10 mM, and a low detection limit of about 50 µM. The long-term stability of the penicillin biosensor was periodically tested over a time period of about one year without any significant loss of sensitivity. The biosensor has also been successfully applied for penicillin detection in bovine milk samples.