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

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

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.

scholarly journals Hyaluronate-Functionalized Graphene for Label-Free Electrochemical Cytosensing

Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 669 ◽  
Author(s):  
Aihua Jing ◽  
Chunxin Zhang ◽  
Gaofeng Liang ◽  
Wenpo Feng ◽  
Zhengshan Tian ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Cancer Cells ◽  
Electrochemical Sensors ◽  
Electrochemical Impedance ◽  
Cyclic Voltammograms ◽  
Cell Detection ◽  
Functionalized Graphene ◽  
Label Free ◽  
Promising Alternative

Electrochemical sensors for early tumor cell detection are currently an important area of research, as this special region directly improves the efficiency of cancer treatment. Functional graphene is a promising alternative for selective recognition and capture of target cancer cells. In our work, an effective cytosensor of hyaluronate-functionalized graphene (HG) was prepared through chemical reduction of graphene oxide. The as-prepared HG nanostructures were characterized with Fourier transform infrared spectroscopy and transmission electron microscopy coupled with cyclic voltammograms and electrochemical impedance spectroscopy, respectively. The self-assembly of HG with ethylene diamine, followed by sodium hyaluronate, enabled the fabrication of a label-free electrochemical impedance spectroscopy cytosensor with high stability and biocompatibility. Finally, the proposed cytosensor exhibited satisfying electrochemical behavior and cell-capture capacity for human colorectal cancer cells HCT-116, and also displayed a wide linear range, from 5.0 × 102 cells∙mL−1 to 5.0 × 106 cells∙mL−1, and a low detection limit of 100 cells∙mL−1 (S/N = 3) for quantification. This work paves the way for graphene applications in electrochemical cytosensing and other bioassays.

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.

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