ANALYTICAL APPLICATIONS OF NUCLEIC ACIDS ELECTROACTIVITY
Marian Filipiak, Mariusz Tichoniuk, Daniela Gwiazdowska and Marta Ligaj
Chair of Biochemistry and Microbiology, Poznan University of Economics,
al. Niepodleglosci 10, 61-875 Poznan/Poland
marian.filipiak@ue.poznan.pl
Electrochemical properties of nucleic acids have been presented in some review papers [1]. In this
work few examples of analytical application of this feature are presented and discussed.
DNA oxidation on carbon electrode emerges in irreversible oxidation of guanine and adenine and
typical DNA voltammogram shows two distinctive peaks of these two bases. Guanine is the easiest
oxidized base and its signal is always present in voltammograms of DNA fragments. The presence
of thymine or cytosine in oligonucleotides is recorded in voltammogram when their contribution is
significantly high, exceeding 50% of all bases [2].
Some low molecular compounds interact with DNA what leads often to nucleic acid damage.
Electrochemical DNA biosensor was developed for detecting specific toxic substance o-dianisidine
[3]. Detection was accomplished by monitoring guanine signal of double-stranded deoxyribonucleic
acid immobilized on carbon paste electrode. In the presence of o-dianisidine guanine response was
reduced to the extent proportional to the analyte concentration. The lowest toxin concentration
detected was 0.4 μM, guanine peak completely disappeared at o-dianisidine concentration 100 μM.
Hybridization biosensors are usually destined for the detection of microorganisms. In this work an
electrochemical biosensor for the detection of Aeromonas hydrophila, foodborne pathogen of
emerging importance is presented. The detection layer of this biosensor was a gold electrode
modified by a self assembled monolayer of thiolated single-stranded DNA probe and alkanethiol as
diluent. The molecular probe was specific to aerolysin, virulence determinant of Aeromonas
hydrophila. Each step of biosensor preparation and final detection of target DNA were carefully
monitored by measuring electrode capacitance, surface density and voltammetric response of
electroactive indicators – hexaammineruthenum chloride and methylene blue.
DNA hybridization biosensors are supposed to be also very useful in detection of genetically
modified food. In this work the biosensor for the detection of bar gene coding fosphinothricin
herbicide resistance is presented. Single-stranded 19-mer DNA probe specific to bar gene was
covalently attached by 5’-phosphate end to the surface of modified carbon paste electrode [4]. The
detection limit of target DNA was 0.1 μM in the presence of noncomplementary DNA fragments.
References
F. Boussicault, M. Robert, Electron transfer in DNA and in DNA-related biological processes.
Electrochemical insight, Chemical Reviews 108(7), 2622, 2008
I. Stempkowska, M. Ligaj, J. Jasnowska, J. Langer and M. Filipiak, Electrochemical response of
oligonucleotides on carbon paste electrode, Bioelectrochemistry 70, 488, 2008
J. Jasnowska, M. Ligaj, B. Stupnicka and M. Filipiak, DNA sensor for o-dianisidine,
Bioelectrochemistry 64, 85, 2004
M. Ligaj, M. Tichoniuk and M. Filipiak, Detection of bar gene encoding phosphinothricin herbicide
resistance in plants by electrochemical biosensor, Bioelectrochemistry 74, 32, 2008
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