TY  - JOUR
A1  - Wu, Chunsheng
A1  - Poghossian, Arshak
A1  - Bronder, Thomas
A1  - Schöning, Michael Josef
T1  - Sensing of double-stranded DNA molecules by their intrinsic molecular charge using the light-addressable potentiometric sensor
JF  - Sensors and Actuators B: Chemical
N2  - A multi-spot light-addressable potentiometric sensor (LAPS), which belongs to the family of semiconductor field-effect devices, was applied for label-free detection of double-stranded deoxyribonucleic acid (dsDNA) molecules by their intrinsic molecular charge. To reduce the distance between the DNA charge and sensor surface and thus, to enhance the electrostatic coupling between the dsDNA molecules and the LAPS, the negatively charged dsDNA molecules were electrostatically adsorbed onto the gate surface of the LAPS covered with a positively charged weak polyelectrolyte layer of PAH (poly(allylamine hydrochloride)). The surface potential changes in each spot of the LAPS, induced by the layer-by-layer adsorption of a PAH/dsDNA bilayer, were recorded by means of photocurrent-voltage and constant-photocurrent measurements. In addition, the surface morphology of the gate surface before and after consecutive electrostatic adsorption of PAH and dsDNA layers was studied by atomic force microscopy measurements. Moreover, fluorescence microscopy was used to verify the successful adsorption of dsDNA molecules onto the PAH-modified LAPS surface. A high sensor signal of 25 mV was registered after adsorption of 10 nM dsDNA molecules. The lower detection limit is down to 0.1 nM dsDNA. The obtained results demonstrate that the PAH-modified LAPS device provides a convenient and rapid platform for the direct label-free electrical detection of in-solution hybridized dsDNA molecules.
KW  - Layer-by-layer adsorption
KW  - Poly(allylamine hydrochloride)
KW  - Label-free detection
KW  - DNA biosensor
KW  - LAPS
KW  - Field effect
Y1  - 2016
U6  - http://dx.doi.org/10.1016/j.snb.2016.02.004
SN  - 0925-4005
IS  - 229
SP  - 506
EP  - 512
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Yoshinobu, T.
A1  - Ecken, H.
A1  - Poghossian, Arshak
A1  - Lüth, H.
A1  - Iwasaki, H.
A1  - Schöning, Michael Josef
T1  - Alternative sensor materials for light-addressable potentiometric sensors
JF  - Sensors and Actuators B. 76 (2001), H. 1-3
Y1  - 2001
SN  - 0925-4005
SP  - 388
EP  - 392
ER  - 
TY  - JOUR
A1  - Yoshinobu, T.
A1  - Ecken, H.
A1  - Poghossian, Arshak
A1  - Simonis, A.
A1  - Iwasaki, H.
A1  - Lüth, H.
A1  - Schöning, Michael Josef
T1  - Constant-current-mode LAPS (CLAPS) for the detection of penicillin
JF  - Electroanalysis. 13 (2001), H. 8-9
Y1  - 2001
SN  - 1040-0397
SP  - 733
EP  - 736
ER  - 
TY  - JOUR
A1  - Yoshinobu, Tatsuo
A1  - Miyamoto, Ko-ichiro
A1  - Werner, Frederik
A1  - Poghossian, Arshak
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Light-addressable potentiometric sensors for quantitative spatial imaging of chemical species
JF  - Annual Review of Analytical Chemistry
N2  - A light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor, in which a measurement site on the sensing surface is defined by illumination. This light addressability can be applied to visualize the spatial distribution of pH or the concentration of a specific chemical species, with potential applications in the fields of chemistry, materials science, biology, and medicine. In this review, the features of this chemical imaging sensor technology are compared with those of other technologies. Instrumentation, principles of operation, and various measurement modes of chemical imaging sensor systems are described. The review discusses and summarizes state-of-the-art technologies, especially with regard to the spatial resolution and measurement speed; for example, a high spatial resolution in a submicron range and a readout speed in the range of several tens of thousands of pixels per second have been achieved with the LAPS. The possibility of combining this technology with microfluidic devices and other potential future developments are discussed.
Y1  - 2017
U6  - http://dx.doi.org/10.1146/annurev-anchem-061516-045158
SN  - 1936-1327
VL  - 10
SP  - 225
EP  - 246
PB  - Annual Reviews
CY  - Palo Alto, Calif.
ER  -