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- capacitive field-effect sensor (3)
- tobacco mosaic virus (TMV) (3)
- field-effect sensor (2)
- gold nanoparticles (2)
- (Bio)degradation (1)
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- Electrolyte–insulator–semiconductor (1)
- Enzyme coverage (1)
- Enzyme logic gate (1)
- Field effect (1)
- Field-effect biosensor (1)
- Field-effect sensor (1)
- Impedance spectroscopy (1)
- LAPS (1)
- Label-free detection (1)
- Layer-by-layer adsorption (1)
- Multianalyte detection (1)
- Penicillin (1)
- Poly(allylamine hydrochloride) (1)
- Poly(d,l-lacticacid) (1)
- Real-time monitoring (1)
- TMV adsorption (1)
- Ta₂O₅ gate (1)
- XOR (1)
- aminooctanethiol (1)
- bi-enzyme biosensor (1)
- biosensor (1)
- capacitive EIS sensor (1)
- capacitive model (1)
- control gate (1)
- detection of charged macromolecules (1)
- electrolyte-insulator-semiconductor capacitors (1)
- enzyme cascade (1)
- enzyme-logic gate (1)
- equivalent circuit (1)
- glucose oxidase (GOx) (1)
- horseradish peroxidase (HRP) (1)
- multianalyte detection (1)
- nanoparticle coverage (1)
- on-chip integrated addressable EISCAP sensors (1)
- penicillinase (1)
- plant virus detection (1)
- polystyrene sulfonate (1)
- turnip vein clearing virus (TVCV) (1)
- urease (1)
Institute
- INB - Institut für Nano- und Biotechnologien (147) (remove)
Planar and three-dimensional (3D) interdigitated electrodes (IDE) with electrode digits separated by an insulating barrier of different heights were electrochemically characterized and compared in terms of their sensing properties. Due to the impact of the surface resistance, both types of IDE structures display a non-linear behavior in low-ionic strength solutions. The experimental data were fitted to an electrical equivalent circuit and interpreted taking into account the surface-charge-governed properties. The effect of a charged polyelectrolyte layer electrostatically assembled onto the sensor surface on the surface resistance in solutions with different KCl concentration is studied. In case of the same electrode footprint, 3D-IDEs show a larger cell constant and a higher sensitivity to molecular adsorption than that of planar IDEs. The obtained results demonstrate the potential of 3D-IDEs as a new transducer structure for a direct label-free sensing of charged molecules.
The presentation of enzymes on viral scaffolds has beneficial effects such as an increased enzyme loading and a prolonged reusability in comparison to conventional immobilization platforms. Here, we used modified tobacco mosaic virus (TMV) nanorods as enzyme carriers in penicillin G detection for the first time. Penicillinase enzymes were conjugated with streptavidin and coupled to TMV rods by use of a bifunctional biotin-linker. Penicillinase-decorated TMV particles were characterized extensively in halochromic dye-based biosensing. Acidometric analyte detection was performed with bromcresol purple as pH indicator and spectrophotometry. The TMV-assisted sensors exhibited increased enzyme loading and strongly improved reusability, and higher analysis rates compared to layouts without viral adapters. They extended the half-life of the sensors from 4 - 6 days to 5 weeks and thus allowed an at least 8-fold longer use of the sensors. Using a commercial budget-priced penicillinase preparation, a detection limit of 100 µM penicillin was obtained. Initial experiments also indicate that the system may be transferred to label-free detection layouts.
Penicillin detection by means of field-effect based sensors: EnFET, capacitive EIS sensor or LAPS?
(2001)
Penicillin detection by means of field-effect based sensors: EnFET, capacitive EIS sensor or LAPS?
(2000)
Optoelectronic Properties of Nanostructured Ensembles Controlled by Biomolecular Logic Systems
(2008)
Novel concepts for flow-rate and flow-direction determination by means of pH-sensitive ISFETs
(2001)
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.