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A correction was published on 15 February 2011, see Sensors 2011, 11(2), 2175-2176.

Sensors 2010, 10(11), 9872-9890; doi:10.3390/s101109872
Article

Electrochemical Aptasensor for Endocrine Disrupting 17β-Estradiol Based on a Poly(3,4-ethylenedioxylthiopene)-Gold Nanocomposite Platform

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Received: 3 August 2010; in revised form: 17 September 2010 / Accepted: 11 October 2010 / Published: 3 November 2010
(This article belongs to the Section Physical Sensors)
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Abstract: A simple and highly sensitive electrochemical DNA aptasensor with high affinity for endocrine disrupting 17β-estradiol, was developed. Poly(3,4-ethylenedioxylthiophene) (PEDOT) doped with gold nanoparticles (AuNPs) was electrochemically synthesized and employed for the immobilization of biotinylated aptamer towards the detection of the target. The diffusion coefficient of the nanocomposite was 6.50 × 10−7 cm2 s−1, which showed that the nanocomposite was highly conducting. Electrochemical impedance investigation also revealed the catalytic properties of the nanocomposite with an exchange current value of 2.16 × 10−4 A, compared to 2.14 × 10−5 A obtained for the bare electrode. Streptavidin was covalently attached to the platform using carbodiimide chemistry and the aptamer immobilized via streptavidin—biotin interaction. The electrochemical signal generated from the aptamer–target molecule interaction was monitored electrochemically using cyclic voltammetry and square wave voltammetry in the presence of [Fe(CN)6]−3/−4 as a redox probe. The signal observed shows a current decrease due to interference of the bound 17β-estradiol. The current drop was proportional to the concentration of 17β-estradiol. The PEDOT/AuNP platform exhibited high electroactivity, with increased peak current. The platform was found suitable for the immobilization of the DNAaptamer. The aptasensor was able to distinguish 17β-estradiol from structurally similar endocrine disrupting chemicals denoting its specificity to 17β-estradiol. The detectable concentration range of the 17β-estradiol was 0.1 nM–100 nM, with a detection limit of 0.02 nM.
Keywords: poly(3,4-ethylenedioxythiophene) (PEDOT); aptamer; modified electrode; avidin/biotin; square wave voltammetry poly(3,4-ethylenedioxythiophene) (PEDOT); aptamer; modified electrode; avidin/biotin; square wave voltammetry
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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MDPI and ACS Style

Olowu, R.A.; Arotiba, O.; Mailu, S.N.; Waryo, T.T.; Baker, P.; Iwuoha, E. Electrochemical Aptasensor for Endocrine Disrupting 17β-Estradiol Based on a Poly(3,4-ethylenedioxylthiopene)-Gold Nanocomposite Platform. Sensors 2010, 10, 9872-9890.

AMA Style

Olowu RA, Arotiba O, Mailu SN, Waryo TT, Baker P, Iwuoha E. Electrochemical Aptasensor for Endocrine Disrupting 17β-Estradiol Based on a Poly(3,4-ethylenedioxylthiopene)-Gold Nanocomposite Platform. Sensors. 2010; 10(11):9872-9890.

Chicago/Turabian Style

Olowu, Rasaq A.; Arotiba, Omotayo; Mailu, Stephen N.; Waryo, Tesfaye T.; Baker, Priscilla; Iwuoha, Emmanuel. 2010. "Electrochemical Aptasensor for Endocrine Disrupting 17β-Estradiol Based on a Poly(3,4-ethylenedioxylthiopene)-Gold Nanocomposite Platform." Sensors 10, no. 11: 9872-9890.



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