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  -