Label-Free Sequence-Specific DNA Sensing Using Copper-Enhanced Anodic Stripping of Purine Bases at Boron-Doped Diamond Electrodes

Stanislav Hasoň,* Hana Pivoňková, Vladimír Vetterl, and Miroslav Fojta*
Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Krlovopolsk 135, CZ-612 65 Brno, Czech Republic
Anal. Chem., 2008, 80 (7), pp 2391–2399
DOI: 10.1021/ac7019305
Publication Date (Web): March 6, 2008
Copyright © 2008 American Chemical Society
*

 To whom correspondence should be addressed. E-mail:  fojta@ibp.cz (M.F.), hasons@ibp.cz (S.H.).

Abstract

Stripping voltammetric determination of purine bases in the presence of copper ions at mercury, amalgam, or carbon-based electrodes has recently been utilized in analysis of DNA or synthetic oligodeoxynucleotides (ODNs). Here we report on copper-enhanced label-free anodic stripping detection of guanine and adenine bases in acid-hydrolyzed DNA at anodically oxidized boron-doped diamond electrode (AO-BDDE). The AO-BDDE was successfully applied in a three-electrode microcell in which an 50 μL drop of the analyte solution can be efficiently stirred during the accumulation step by streaming of an inert gas. Accelerated mass transport due to the solution motion in the presence of copper resulted in enhancement of the guanine oxidation signal by about 2 orders of magnitude (compared to accumulation of the analyte from still solution not containing copper), allowing an easy detection of 25 fmol of the ODNs. The proposed technique is shown to be suitable for a determination of purine (particularly guanine) content in DNA samples. Applications of the technique in magnetic bead-based DNA assays (such as hybridization with DNA sequences exhibiting asymmetrical distribution of purine/pyrimidine nucleotides between the complementary strands or monitoring of amplification of specific DNA fragments in a duplex polymerase chain reaction) are demonstrated.

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History

  • Published In Issue April 01, 2008
  • Received for review September 14, 2007. Accepted December 15, 2007.

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