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Label‐free electrical detection of DNA by means of field‐effect nanoplate capacitors: Experiments and modeling
Author(s) -
Abouzar Maryam H.,
Poghossian Arshak,
Cherstvy Andrey G.,
Pedraza Angela M.,
Ingebrandt Sven,
Schöning Michael J.
Publication year - 2012
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201100710
Subject(s) - denaturation (fissile materials) , dna–dna hybridization , materials science , biosensor , dna , hybridization probe , ionic bonding , nucleic acid thermodynamics , analytical chemistry (journal) , biophysics , chemistry , nanotechnology , ion , biochemistry , biology , chromatography , nuclear chemistry , organic chemistry , base sequence
Label‐free electrical detection of consecutive deoxyribonucleic acid (DNA) hybridization/denaturation by means of an array of individually addressable field‐effect‐based nanoplate silicon‐on‐insulator (SOI) capacitors modified with gold nanoparticles (Au‐NP) is investigated. The proposed device detects charge changes on Au‐NP/DNA hybrids induced by the hybridization or denaturation event. DNA hybridization was performed in a high ionic‐strength solution to provide a high hybridization efficiency. On the other hand, to reduce the screening of the DNA charge by counter ions and to achieve a high sensitivity, the sensor signal induced by the hybridization and denaturation events was measured in a low ionic‐strength solution. High sensor signals of about 120, 90, and 80 mV were registered after the DNA hybridization, denaturation, and re‐hybridization events, respectively. Fluorescence microscopy has been applied as reference method to verify the DNA immobilization, hybridization, and denaturation processes. An electrostatic charge‐plane model for potential changes at the gate surface of a nanoplate field‐effect sensor induced by the DNA hybridization has been developed taking into account both the Debye length and the distance of the DNA charge from the gate surface.