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Nanostructure film modified electrodes for the preparation of DNA biosensors

Adriana Ferancova 1Ludmila Heilerova 2Jiří Zima 3Jiří Barek 3Jan Labuda 1

1. Slovak University of Technology, Department of Analytical Chemistry, Bratislava 81237, Slovakia (Slovak Rep.)
2. Food Research Institute Bratislava, Biocentre Modra, Kostolna 7, Modra 90001, Slovakia (Slovak Rep.)
3. Charles University, UNESCO Laboratory of Environmental Electrochemistry, Albertov 6, Prague 12843, Czech Republic

DNA modified electrodes have found a wide popularity among sensors for the biochemically related analysis. A variety of commertial electrode substrates was used to transduce the signal. In recent years, different nanostructured materials have became the subject of intensive investigations and applications because of their unique mechanical, electrical, optical and thermal properties. Nanoobjects such as nanoparticles of metals, semiconductors, oxides and nanostructures such as nanotubes and nanowires could significantly improve the sensitivity of electrochemical sensors and biosensors.

Nanostructured films of multi-wall carbon nanotubes, hydroxyapatite and montmorillonite were deposited at the surface of a working electrode of the commercial carbon paste-based screen-printed assembly (SPE) and utilized for the surface modification with the double-stranded DNA using layer-to-layer coverage and mixed (composite) coverage. The surface morphology of the sensors was investigated using scanning electron microscopy. The DNA redox marker [Co(phen)3]3+ and ferrocyanide ion were used for the investigation of basic electrochemical properties of the sensors using differential pulse voltammetry and cyclic voltammetry. The modified electrodes were characterized also by electrochemical impedance measurements.

The DNA-based biosensors showed good repeability of the signal as well as necessary stability within several days. A relative enhancement of the DNA signals at the SPE electrodes with nanostructured films comparing to the simple DNA modified SPE, which is neccessary for the detection of DNA binding and damage interactions, was found. DNA biosensors based on carbon nanotubes were also applied to the detection of damage to DNA.

Acknowledgement: This work was supported by the Grant Agency APVT (No. 27-010304 and No. 20-015904) and by the Grant Agency of the Czech Republic (No. 203/03/0182).


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Presentation: Short communication at SMCBS'2005 Workshop, by Adriana Ferancova
See On-line Journal of SMCBS'2005 Workshop

Submitted: 2005-09-05 12:56
Revised:   2009-06-07 00:44