scholarly journals Semi-analytical dynamic modeling of DNA surface-hybridization via AC Electro-kinetic steering

2020 ◽  
Author(s):  
P. Capaldo ◽  
S. D. Zilio ◽  
V. Torre ◽  
Y. Yang
Keyword(s):  
Electric Fields ◽  
Dna Hybridization ◽  
Electrochemical Impedance ◽  
Dynamic Properties ◽  
Label Free ◽  
Buffer Solution ◽  
Self Assembled Monolayer ◽  
Reliable Determination ◽  
Design And Optimization ◽  
Solid Gold

ABSTRACTThe change in electrical property (capacitance) upon hybridization of the desired ssDNA to a capture probe has been proposed as a promising technology platform in biomedical research and practice. An appropriate mathematical model is needed for understanding and optimizing the process occurring at the electrode/electrolyte interface. It is also informative for examining the forces generated by the AC electric fields on the DNA molecules as well as the suspending buffer solution in the experimental pool. Here, we provide the development, formulation and validation of a semi-analytical model of DNA hybridization with deoxynucleotide molecules chemically tethered to a solid gold electrode. The parameters of the proposed model have been estimated using available experimental data. We demonstrate that the detection limit and specificity of our surface-based genosensor are not only dependent on the probe/target binding affinity, but also on the Self-Assembled Monolayer (SAM) density and on the interfacial electric field. The label-free Electrochemical Impedance Spectroscopy (EIS)-based oligonucleotide biosensor with integrated DC-biased can achieve rapid hybridization, high selectivity and sensitive detection for DNA target samples.SIGNIFICANCEDNA hybridization, wherein strands of DNA form duplex through noncovalent, sequence-specific interactions, is one of the most fundamental processes in biology. Fast and reliable determination of miniature amounts of DNA plays important role in clinical forensic and pharmaceutical applications. Thus, developing a better understanding of the kinetic and dynamic properties of DNA hybridization will help in the elucidation of all mechanisms involved in numerous biochemical processes. Moreover, because DNA hybridization has been widely adapted in biotechnology, its study is invaluable to the development of a range of commercially important processes.To achieve optimal sensitivity with minimum sample size and rapid hybridization, ability to predict the kinetics of hybridization based on the characteristics of the strands is crucial, and hence a computer aided numerical model for the design and optimization of a DNA biosensor has been implemented.

A microfluidic device with integrated impedance detection for λ-DNA

2003 ◽  
Vol 773 ◽  
Author(s):  
Myung-Il Park ◽  
Jonging Hong ◽  
Dae Sung Yoon ◽  
Chong-Ook Park ◽  
Geunbae Im
Keyword(s):  
Microfluidic Device ◽  
Electrochemical Impedance ◽  
Direct Detection ◽  
Full Potential ◽  
Label Free ◽  
Buffer Solution ◽  
Detection Systems ◽  
Significant Difference ◽  
Detection Of Biomolecules ◽  
Impedance Magnitude

AbstractThe large optical detection systems that are typically utilized at present may not be able to reach their full potential as portable analysis tools. Accurate, early, and fast diagnosis for many diseases requires the direct detection of biomolecules such as DNA, proteins, and cells. In this research, a glass microchip with integrated microelectrodes has been fabricated, and the performance of electrochemical impedance detection was investigated for the biomolecules. We have used label-free λ-DNA as a sample biomolecule. By changing the distance between microelectrodes, the significant difference between DW and the TE buffer solution is obtained from the impedance-frequency measurements. In addition, the comparison for the impedance magnitude of DW, the TE buffer, and λ-DNA at the same distance was analyzed.

Breast cancer detection using charge sensors coupled to DNA monolayer

2015 ◽  
Vol 1793 ◽  
pp. 19-26
Author(s):  
Marina R. Batistuti ◽  
Marcelo Mulato ◽  
Paulo R. Bueno
Keyword(s):  
Breast Cancer ◽  
Dna Sequence ◽  
Dna Sequences ◽  
Electrochemical Impedance ◽  
Redox System ◽  
Charge Transfer Resistance ◽  
Label Free ◽  
Self Assembled Monolayer ◽  
Transfer Resistance ◽  
Complementary Dna

ABSTRACTWe report the development of a label-free biosensors based on DNA hybridization, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). This study uses DNA sequences based on microRNA related with breast cancer. The biosensor was fabricated by immobilizing a self-assembled monolayer of single-stranded 23-mer oligonucleotide (ssDNA) via a thiol linker on gold work electrodes. Residual binding places were filled with 6 -mercaptohexanol (MCH). The electrode was electrochemicaly characterized in the presence of a redox system ferri/ferrocyanide. Different concentrations of complementary DNA sequence for hybridization were incubated; an increase of charge transfer resistance (Rct) was observed, used as sensor parameter and correlated with concentrations of complementary DNA sequence. A debate was presented on the effect of the MgCl2 influence on ssDNA immobilization solution.

scholarly journals Electrochemical Detection Platform Based on RGO Functionalized with Diazonium Salt for DNA Hybridization

Biosensors ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 39
Author(s):  
Elena A. Chiticaru ◽  
Luisa Pilan ◽  
Mariana Ioniţă
Keyword(s):  
Charge Transfer ◽  
Dna Hybridization ◽  
Electrochemical Impedance ◽  
Diazonium Salt ◽  
Modified Electrodes ◽  
Covalent Immobilization ◽  
Fabrication Process ◽  
Label Free ◽  
Modified Dna ◽  
Electron Transfer Properties

In this paper, we propose an improved electrochemical platform based on graphene for the detection of DNA hybridization. Commercial screen-printed carbon electrodes (SPCEs) were used for this purpose due to their ease of functionalization and miniaturization opportunities. SPCEs were modified with reduced graphene oxide (RGO), offering a suitable surface for further functionalization. Therefore, aryl-carboxyl groups were integrated onto RGO-modified electrodes by electrochemical reduction of the corresponding diazonium salt to provide enough reaction sites for the covalent immobilization of amino-modified DNA probes. Our final goal was to determine the optimum conditions needed to fabricate a simple, label-free RGO-based electrochemical platform to detect the hybridization between two complementary single-stranded DNA molecules. Each modification step in the fabrication process was monitored by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using [Fe(CN)6]3−/4− as a redox reporter. Although, the diazonium electrografted layer displayed the expected blocking effect of the charge transfer, the next steps in the modification procedure resulted in enhanced electron transfer properties of the electrode interface. We suggest that the improvement in the charge transfer after the DNA hybridization process could be exploited as a prospective sensing feature. The morphological and structural characterization of the modified electrodes performed by scanning electron microscopy (SEM) and Raman spectroscopy, respectively, were used to validate different modification steps in the platform fabrication process.

Label-free electrochemical impedance sensing of DNA hybridization based on functionalized graphene sheets

2011 ◽  
Vol 47 (6) ◽  
pp. 1743-1745 ◽  
Author(s):  
Yuwei Hu ◽  
Fenghua Li ◽  
Xiaoxue Bai ◽  
Dan Li ◽  
Shucheng Hua ◽  
...  
Keyword(s):  
Dna Hybridization ◽  
Electrochemical Impedance ◽  
Graphene Sheets ◽  
Functionalized Graphene ◽  
Label Free ◽  
Impedance Sensing

scholarly journals An Electrochemical Immunosensor Based on a Self-Assembled Monolayer Modified Electrode for Label-Free Detection of α-Synuclein

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 617 ◽  
Author(s):  
Chuang-Ye Ge ◽  
Md. Mahbubur Rahman ◽  
Wei Zhang ◽  
Nasrin Siraj Lopa ◽  
Lei Jin ◽  
...  
Keyword(s):  
Dynamic Range ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Label Free ◽  
Serum Samples ◽  
Self Assembled Monolayer ◽  
Electrochemical Impedance Spectra ◽  
Transfer Resistance ◽  
Label Free Detection ◽  
Self Assembled

This research demonstrated the development of a simple, cost-effective, and label-free immunosensor for the detection of α-synuclein (α-Syn) based on a cystamine (CYS) self-assembled monolayer (SAM) decorated fluorine-doped tin oxide (FTO) electrode. CYS-SAM was formed onto the FTO electrode by the adsorption of CYS molecules through the head sulfur groups. The free amine (–NH2) groups at the tail of the CYS-SAM enabled the immobilization of anti-α-Syn-antibody, which concurrently allowed the formation of immunocomplex by covalent bonding with α-Syn-antigen. The variation of the concentrations of the attached α-Syn at the immunosensor probe induced the alternation of the current and the charge transfer resistance (Rct) for the redox response of [Fe(CN)6]3−/4−, which displayed a linear dynamic range from 10 to 1000 ng/mL with a low detection limit (S/N = 3) of ca. 3.62 and 1.13 ng/mL in differential pulse voltammetry (DPV) and electrochemical impedance spectra (EIS) measurements, respectively. The immunosensor displayed good reproducibility, anti-interference ability, and good recoveries of α-Syn detection in diluted human serum samples. The proposed immunosensor is a promising platform to detect α-Syn for the early diagnose of Parkinson’s disease, which can be extended for the determination of other biologically important biomarkers.

Green-synthesized gold nanoparticles decorated graphene sheets for label-free electrochemical impedance DNA hybridization biosensing

2011 ◽  
Vol 26 (11) ◽  
pp. 4355-4361 ◽  
Author(s):  
Yuwei Hu ◽  
Shucheng Hua ◽  
Fenghua Li ◽  
Yuanyuan Jiang ◽  
Xiaoxue Bai ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Dna Hybridization ◽  
Electrochemical Impedance ◽  
Graphene Sheets ◽  
Label Free
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