Electrochemical Transduction of DNA Hybridization by Long-Range Electron Transfer

Elicia L. S. Wong; J. Justin Gooding

doi:10.1071/CH04265

RESEARCH ARTICLE

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Electrochemical Transduction of DNA Hybridization by Long-Range Electron Transfer

Elicia L. S. Wong ^A and J. Justin Gooding ^A ^B

+ Author Affiliations

- Author Affiliations

^A School of Chemistry, University of New South Wales, Sydney NSW 2052, Australia.

^B Corresponding author. Email: justin.gooding@unsw.edu.au

Australian Journal of Chemistry 58(4) 280-287 https://doi.org/10.1071/CH04265
Submitted: 9 November 2004 Accepted: 7 January 2005 Published: 5 April 2005

Abstract

For the detection of DNA hybridization, there are two main challenges that current research aims to overcome: lower detection limits and higher selectivity. We describe here the development of an electrochemical biosensor that used redox-active intercalators to transduce DNA hybridization by long-range electron transfer through DNA duplexes. This study outlines how the sensitivity and selectivity of the biosensor was tuned by careful control of the surface chemistry of the DNA-modified interface. The DNA-modified interface is composed of thiolated DNA and a diluent component, both of which are self-assembled onto a gold electrode. The resultant DNA biosensor has excellent selectivity towards single-base mismatch detection, whilst both the detection limit and sensitivity can easily be adjusted by varying the length of the diluent molecule relative to the length of the thiol linker at the 3´ end of the DNA. The one limitation of such a detection scheme is the slow assay time, which is a consequence of the slow kinetics of intercalation of the redox molecule into the duplexes. Approaches to reducing the assay time to a more commercially viable timescale are outlined.

Acknowledgment

We thank the Australian Research Council (ARC) for funding this project.

References

Electrochemical Transduction of DNA Hybridization by Long-Range Electron Transfer

Abstract

Acknowledgment

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