Carbon-nanotube-modified glassy carbon electrodes for amplified label-free electrochemical detection of DNA hybridization

Abstract

The preparation and attractive performance of carbon-nanotube modified glassy-carbon (CNT/GC) electrodes for improved detection of purines, nucleic acids, and DNA hybridization are described. The surface-confined multiwall carbon-nanotube (MWCNT) facilitates the adsorptive accumulation of the guanine nucleobase and greatly enhances its oxidation signal. The advantages of CNT/GC electrodes are illustrated from comparison to the common unmodified glassy carbon, carbon paste and graphite pencil electrodes. The dramatic amplification of the guanine signal has been combined with a label-free electrical detection of DNA hybridization. Factors influencing the enhancement of the guanine signal are assessed and optimized. The performance characteristics of the amplified label-free electrochemical detection of DNA hybridization are reported in connection to measurements of nucleic-acid segments related to the breast-cancer BRCA1 gene.

Mediated amperometric immunosensing using single walled carbon nanotube forests

“…Recently there have been several reports on their application in the area of electrochemical biosensing. [7][8][9][10][11][12][13][14][15][16][17] Their nanometer dimensions, combined with high electrical conductivity, may promote electron transfer to and from redox proteins including cytochrome c, 7 horseradish peroxidase (HRP), 8 myoglobin, and glucose oxidase. 9 This has allowed the sensitive detection of glucose, hydrogen peroxide and nitric oxide.…”

Detection of Sequence-Specific Gene by Multi-Channel Electrochemical DNA Chips

“…Using potassium ferricyanide as electrochemical indicator, the device could be used to recognize reliably not only synthetic sequence-specific DNA but also LAMP products. Though the detection limit of target DNA is larger than that obtained at solo DNA sensor as outlined in the references, [7][8][9][10]32 this can be developed by using some special indicators, such as Hoechst 33258, 4,33 [Ru(NH 3 ) 6 ] 3+ 20 and so on. In fact in this study we focus on many other attractive advantages of the electrochemical chip.…”

“…5,6 Therefore, a lot of achievements have been obtained in the detection of DNA by electrochemical methods. 5,[7][8][9][10][11][12][13] Over the past years, our research groups have also focused on the development of electrochemical DNA hybridization biosensors.…”

Synthesis and Biomedical Applications of Graphene: Present and Future Trends

“…Labelled approached DNA sensors are based on the use of redox indicators to make a distinction between the signal and ds-DNA on the electrode [71]. Millan et al used Co(phen)3 3+ as a redox indicator to probe the ssDNA hybridization with the glassy carbon electrode and observed a much better response in comparison to the ss-DNA on glassy carbon electrode.…”

“…Thus label-free DNA sensing approach is a promising way to avoid any complications for the device fabrication. It is also a cost effective and more accurate method based on intrinsic electroactivity of nucleobases [71,72].…”