TY  - JOUR
A1  - Karschuck, Tobias
A1  - Kaulen, Corinna
A1  - Poghossian, Arshak
A1  - Wagner, Patrick H.
A1  - Schöning, Michael Josef
T1  - Gold nanoparticle-modified capacitive field-effect sensors: Studying the surface density of nanoparticles and coupling of charged polyelectrolyte macromolecules
JF  - Electrochemical Science Advances
N2  - The coupling of ligand-stabilized gold nanoparticles with field-effect devices offers new possibilities for label-free biosensing. In this work, we study the immobilization of aminooctanethiol-stabilized gold nanoparticles (AuAOTs) on the silicon dioxide surface of a capacitive field-effect sensor. The terminal amino group of the AuAOT is well suited for the functionalization with biomolecules. The attachment of the positively-charged AuAOTs on a capacitive field-effect sensor was detected by direct electrical readout using capacitance-voltage and constant capacitance measurements. With a higher particle density on the sensor surface, the measured signal change was correspondingly more pronounced. The results demonstrate the ability of capacitive field-effect sensors for the non-destructive quantitative validation of nanoparticle immobilization. In addition, the electrostatic binding of the polyanion polystyrene sulfonate to the AuAOT-modified sensor surface was studied as a model system for the label-free detection of charged macromolecules. Most likely, this approach can be transferred to the label-free detection of other charged molecules such as enzymes or antibodies.
KW  - polystyrene sulfonate
KW  - gold nanoparticles
KW  - field-effect sensor
KW  - detection of charged macromolecules
KW  - capacitive EIS sensor
Y1  - 2021
U6  - http://dx.doi.org/10.1002/elsa.202100179
SN  - 0938-5193
VL  - 2
IS  - 5
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Bronder, Thomas
A1  - Wu, Chunsheng
A1  - Poghossian, Arshak
A1  - Werner, Frederik
A1  - Keusgen, M.
A1  - Schöning, Michael Josef
T1  - Label-free detection of DNA hybridization with light-addressable potentiometric sensors: comparison of various DNA-immobilization strategies
JF  - Procedia Engineering
N2  - Light-addressable potentiometric sensors (LAPS) consisting of a p-Si-SiO2 and p-Si-SiO2-Au structure, respectively, have been tested for a label-free electrical detection of DNA (deoxyribonucleic acid) hybridization. Three different strategies for immobilizing single-stranded probe DNA (ssDNA) molecules on a LAPS surface have been studied and compared: (a) immobilization of thiol-modified ssDNA on the patterned Au surface via gold-thiol bond, (b) covalent immobilization of amino-modified ssDNA onto the SiO2 surface functionalized with 3-aminopropyltriethoxysilane and (c) layer-by-layer adsorption of negatively charged ssDNA on a positively charged weak polyelectrolyte layer of poly(allylamine hydrochloride).
KW  - LAPS
KW  - lable-free detection
KW  - DNA hybridization
KW  - field-effect sensor
Y1  - 2014
U6  - http://dx.doi.org/10.1016/j.proeng.2014.11.647
SN  - 1877-7058
N1  - EUROSENSORS 2014 ; European Conference on Solid-State Transducers <28, 2014>
VL  - 87
SP  - 755
EP  - 758
PB  - Elsevier
CY  - Amsterdam
ER  -