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Electrochemical Investigation of oligonucleotide-DNA hybridization on poly(4-methoxyphenethylamine).

Silva FB, Vieira SN, Goulart LR - Int J Mol Sci (2008)

Bottom Line: However, when immobilized onto the poly(4-methoxyphenethylamine), a significant increase in the magnitude of the current was obtained.Hybridization results in a decrease of the peak current of guanosine and adenosine or the signal of methylene blue accumulated on the modified electrode surface.The results showed a significant modification in the Nyquist plot, after addition of the complementary target, with increase of the charge transference resistance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Chemistry, Federal University of Uberlândia, Brazil. fran_ciellesilva@hotmail.com <fran_ciellesilva@hotmail.com>

ABSTRACT
This work describes the immobilization of purine and pyrimidine bases and immobilization/hybridization of synthetic oligonucleotides on graphite electrodes modified with poly(4-methoxyphenethylamine) produced in acid medium. The immobilization of adenine, guanine, cytosine and thymine on these modified electrodes was efficient, producing characteristic peaks. Another relevant observation is that, according to the literature, pyrimidine bases, cytosine and thymine are more difficult to detect. However, when immobilized onto the poly(4-methoxyphenethylamine), a significant increase in the magnitude of the current was obtained. The observation of the hybridization between the poly(GA) probe and its complementary, poly(CT) target, was possible by monitoring the guanosine and adenosine peaks or through methylene blue indicator, using differential pulse voltammetry. Hybridization results in a decrease of the peak current of guanosine and adenosine or the signal of methylene blue accumulated on the modified electrode surface. The hybridization with the complementary target was also investigated by electrochemical impedance spectroscopy. The results showed a significant modification in the Nyquist plot, after addition of the complementary target, with increase of the charge transference resistance.

No MeSH data available.


Methylene blue reduction at a solid substrate [37].
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f10-ijms-9-7-1173: Methylene blue reduction at a solid substrate [37].

Mentions: The decrease in the values of the reduction current is governed by the specific interactions between methylene blue and free guanine, with lesser accessibility of methylene blue to guanine in hybridized DNA [40]. The electron transfer between the electrode and the indicator (methylene blue) is in this form, substantially modified due to the smaller amount of species in the presence of the double strand DNA passing from the oxidized state to the reduced state, Figure 10 [37]. This fact is in agreement with the obtained results (see Figure 9).


Electrochemical Investigation of oligonucleotide-DNA hybridization on poly(4-methoxyphenethylamine).

Silva FB, Vieira SN, Goulart LR - Int J Mol Sci (2008)

Methylene blue reduction at a solid substrate [37].
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2635724&req=5

f10-ijms-9-7-1173: Methylene blue reduction at a solid substrate [37].
Mentions: The decrease in the values of the reduction current is governed by the specific interactions between methylene blue and free guanine, with lesser accessibility of methylene blue to guanine in hybridized DNA [40]. The electron transfer between the electrode and the indicator (methylene blue) is in this form, substantially modified due to the smaller amount of species in the presence of the double strand DNA passing from the oxidized state to the reduced state, Figure 10 [37]. This fact is in agreement with the obtained results (see Figure 9).

Bottom Line: However, when immobilized onto the poly(4-methoxyphenethylamine), a significant increase in the magnitude of the current was obtained.Hybridization results in a decrease of the peak current of guanosine and adenosine or the signal of methylene blue accumulated on the modified electrode surface.The results showed a significant modification in the Nyquist plot, after addition of the complementary target, with increase of the charge transference resistance.

View Article: PubMed Central - PubMed

Affiliation: Institute of Chemistry, Federal University of Uberlândia, Brazil. fran_ciellesilva@hotmail.com <fran_ciellesilva@hotmail.com>

ABSTRACT
This work describes the immobilization of purine and pyrimidine bases and immobilization/hybridization of synthetic oligonucleotides on graphite electrodes modified with poly(4-methoxyphenethylamine) produced in acid medium. The immobilization of adenine, guanine, cytosine and thymine on these modified electrodes was efficient, producing characteristic peaks. Another relevant observation is that, according to the literature, pyrimidine bases, cytosine and thymine are more difficult to detect. However, when immobilized onto the poly(4-methoxyphenethylamine), a significant increase in the magnitude of the current was obtained. The observation of the hybridization between the poly(GA) probe and its complementary, poly(CT) target, was possible by monitoring the guanosine and adenosine peaks or through methylene blue indicator, using differential pulse voltammetry. Hybridization results in a decrease of the peak current of guanosine and adenosine or the signal of methylene blue accumulated on the modified electrode surface. The hybridization with the complementary target was also investigated by electrochemical impedance spectroscopy. The results showed a significant modification in the Nyquist plot, after addition of the complementary target, with increase of the charge transference resistance.

No MeSH data available.