Refine
Year of publication
- 2015 (126) (remove)
Institute
- Fachbereich Medizintechnik und Technomathematik (43)
- INB - Institut für Nano- und Biotechnologien (31)
- Fachbereich Wirtschaftswissenschaften (23)
- Fachbereich Chemie und Biotechnologie (20)
- IfB - Institut für Bioengineering (11)
- Fachbereich Energietechnik (9)
- Fachbereich Maschinenbau und Mechatronik (9)
- Fachbereich Elektrotechnik und Informationstechnik (8)
- Fachbereich Luft- und Raumfahrttechnik (6)
- Fachbereich Architektur (4)
Document Type
- Article (126) (remove)
Keywords
- Booster Station (1)
- Discrete Optimization (1)
- Gamma distribution (1)
- Goodness-of-fit test (1)
- Independence test (1)
- Parametric bootstrap (1)
- Pump System (1)
- Technical Operations Research (TOR) (1)
- Vapnik–Čhervonenkis class (1)
- availability (1)
Capacitive field-effect sensors modified with a multi-enzyme membrane have been applied for an electronic transduction of biochemical signals processed by enzyme-based AND-Reset and OR-Reset logic gates. The local pH change at the sensor surface induced by the enzymatic reaction was used for the activation of the Reset function for the first time.
A multi-spot (16 spots) light-addressable potentiometric sensor (MLAPS) consisting of an Al–p-Si–SiO2 structure modified with a weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)) was applied for the label-free electrical detection of DNA (deoxyribonucleic acid) immobilization and hybridization by the intrinsic molecular charge for the first time. To achieve a preferentially flat orientation of DNA strands and thus, to reduce the distance between the DNA charge and MLAPS surface, the negatively charged probe single-stranded DNAs (ssDNA) were electrostatically adsorbed onto the positively charged PAH layer using a simple layer-by-layer (LbL) technique. In this way, more DNA charge can be positioned within the Debye length, yielding a higher sensor signal. The surface potential changes in each spot induced due to the surface modification steps (PAH adsorption, probe ssDNA immobilization, hybridization with complementary target DNA (cDNA), non-specific adsorption of mismatched ssDNA) were determined from the shifts of photocurrent–voltage curves along the voltage axis. A high sensor signal of 83 mV was registered after immobilization of probe ssDNA onto the PAH layer. The hybridization signal increases from 5 mV to 32 mV with increasing the concentration of cDNA from 0.1 nM to 5 μM. In contrast, a small signal of 5 mV was recorded in the case of non-specific adsorption of fully mismatched ssDNA (5 μM). The obtained results demonstrate the potential of the MLAPS in combination with the simple and rapid LbL immobilization technique as a promising platform for the future development of multi-spot light-addressable label-free DNA chips with direct electrical readout.