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Published October 24, 2003 | public
Journal Article

DNA Electrochemistry as a Probe of Base Pair Stacking in A-, B-, and Z-Form DNA


DNA-mediated charge transport (CT) chemistry is sensitive to DNA structure and base pair stacking. In an electrochemical assay based upon DNA CT, DNA-modified electrode surfaces are used to examine the electrochemical reduction of methylene blue (MB), a small molecule that binds to the DNA film by intercalation. Here electrochemically we probe CT in the three primary conformations of double-stranded nucleic acids, A-, B-, and Z-form DNA. The A-form is examined in the context of a DNA/RNA hybrid duplex and Z-DNA, in duplexes containing d(^(m)CG)_8 sequences at high Mg^(2+) concentrations. We find that both A- and B-DNA support efficient DNA CT as measured by MB reduction in the DNA film; a lower level of reduction is evident with the Z-form film. Furthermore, mismatches incorporated into A-form duplexes, as in B-form duplexes, disrupt MB reduction, thus providing a strategy for mutation detection through testing of RNA transcripts at DNA electrodes.

Additional Information

© 2003 American Chemical Society. Received August 5, 2003; Revised Manuscript Received September 11, 2003; Publication Date (Web): October 24, 2003. We are grateful to the National Institutes of Health (GM61077) for their financial support of this research and to Melanie O'Neill for assistance with DNA figures.

Additional details

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October 17, 2023