Details

Autor(en) / Beteiligte

• García-González, Raquel
• Costa-García, Agustín
• Fernández-Abedul, M. Teresa

Titel

Methylene blue covalently attached to single stranded DNA as electroactive label for potential bioassays

Ist Teil von

• Sensors and actuators. B, Chemical, 2014-02, Vol.191, p.784-790

Ort / Verlag

Switzerland: Elsevier B.V

Erscheinungsjahr

2014

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• Methylene blue is an electroactive molecule that has been employed for the detection of the DNA hybridization event in electrochemical sensors. However, its use as a covalent label is very scarce and in most of the cases, non-covalent interactions (hydrophobic, electrostatic) are employed. Although it has advantages as simplicity and fewer number of procedure steps, the covalent attachment is less exploited in the development of these sensors. In this article, the electrochemical behavior of methylene blue attached to different DNA-strands is studied. Several lengths (15- and 30-mer) and different degree of DNA modification (MB-DNA, MB-DNA-MB and MB-DNA-SH) have been studied. The highest signals were obtained for longer strands with two MB molecules. In all the cases the signal is enhanced by CNT-nanostructuration of the electrode. Adsorption on these modified screen-printed electrodes allowed the amplification by employing an accumulation time. In this way, a sensitivity of −0.2864μAμM−1 and a limit of detection of 800nM for a 120s accumulation time were obtained.