TY  - JOUR
A1  - Abouzar, Maryam H.
A1  - Poghossian, Arshak
A1  - Cherstvy, Andrey G.
A1  - Pedraza, Angela M.
A1  - Ingebrandt, Sven
A1  - Schöning, Michael J.
T1  - Label-free electrical detection of DNA by means of field-effect nanoplate capacitors experiments and modeling
JF  - Physica status solidi : A, Applications and materials science
N2  - 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.
KW  - DNA
KW  - field-effect
KW  - gold nanoparticle
KW  - label-free detection
KW  - nanoplate capacitor
Y1  - 2012
U6  - https://doi.org/10.1002/pssa.201100710
SN  - 1862-6300
VL  - 209
IS  - 5
SP  - 925
EP  - 934
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Cherstvy, Andrey G.
A1  - Teif, Vladimir B.
T1  - Electrostatic effect of H1-histone protein binding on nucleosome repeat length
JF  - Physical biology : a journal for the fundamental understanding of biological systems
N2  - Within a simple biophysical model we describe the effect of electrostatic binding of H1 histone proteins on the nucleosome repeat length in chromatin. The length of wrapped DNA optimizes its binding energy to the histone core and the elastic energy penalty of DNA wrapping. The magnitude of the effect predicted from our model is in agreement with the systematic experimental data on the linear variation of nucleosome repeat lengths with H1/nucleosome ratio (Woodcock C L et al 2006 Chromos. Res. 14 17-25). We compare our model to the data for different cell types and organisms, with a widely varying ratio of bound H1 histones per nucleosome. We underline the importance of this non-specific histone-DNA charge-balance mechanism in regulating the positioning of nucleosomes and the degree of compaction of chromatin fibers in eukaryotic cells.
KW  - electrostatics
KW  - DNA
KW  - nucleosome
Y1  - 2014
U6  - https://doi.org/10.1088/1478-3975/11/4/044001
SN  - 1478-3967
SN  - 1478-3975
VL  - 11
IS  - 4
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Heinsohn, Natascha Katharina
A1  - Niedl, Robert Raimund
A1  - Anielski, Alexander
A1  - Lisdat, Fred
A1  - Beta, Carsten
T1  - Electrophoretic mu PAD for purification and analysis of DNA samples
JF  - Biosensors : open access journal
N2  - In this work, the fabrication and characterization of a simple, inexpensive, and effective microfluidic paper analytic device (mu PAD) for monitoring DNA samples is reported. The glass microfiber-based chip has been fabricated by a new wax-based transfer-printing technique and an electrode printing process. It is capable of moving DNA effectively in a time-dependent fashion. The nucleic acid sample is not damaged by this process and is accumulated in front of the anode, but not directly on the electrode. Thus, further DNA processing is feasible. The system allows the DNA to be purified by separating it from other components in sample mixtures such as proteins. Furthermore, it is demonstrated that DNA can be moved through several layers of the glass fiber material. This proof of concept will provide the basis for the development of rapid test systems, e.g., for the detection of pathogens in water samples.
KW  - microfluidic paper analytic device (mu PAD)
KW  - patterning glass microfiber
KW  - fiber-electrophoresis chip
KW  - DNA
KW  - imprinted electrodes
KW  - cross layer chip
KW  - polymerase chain reaction (PCR)
KW  - purification
Y1  - 2022
U6  - https://doi.org/10.3390/bios12020062
SN  - 2079-6374
VL  - 12
IS  - 2
PB  - MDPI
CY  - Basel
ER  -