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.
References
[1]
Stelian, L; Ion, I; Alina, CI. Voltammetric Determination of Phenol at Platinum Electrodes Modified with Polypyrole Doped with Ferricyanide. Rev. Roum. Chim？2009, 54, 351–357.
Xiaoxia, L; Honglan, Q; Lihua, S; Qiang, G; Chengxiao, Z. Electrochemical Aptasensor for the Dteremination of Cocaine Incorporating Gold Nanoparticles Modification. Electroanalysis？2008, 20, 1475–1482.
[4]
Aixue, L; Yang, F; Ma, Y; Yang, XR. Electrochemical Impedance Detection of DNA Hybridization Based on Dendrimer Modified Electrode. Biosens. Bioelectron？2007, 22, 1716–1722.
[5]
Zhao, G-C; Yang, X. A Label-Free Electrochemical RNA Aptamer for Selective Detection of Theophylline. Electrochem. Commun？2010, 12, 300–302.
[6]
Mathebe, NGR; Morrin, A; Iwuoha, EI. Electrochemistry and Scanning Electron Microscopy of Polyaniline/Peroxidase-Based Biosensor. Talanta？2004, 64, 115–120.
[7]
Sakmeche, N; Bazzaoui, EA; Fall, M; Aeiyach, S; Jouini, M; Lacroix, JC; Aaron, JJ; Lacaze, PC. Application of Sodium Dodecyl Sulphate (SDS) Micellar Solution as an Organised Medium for Electropolymerization of Thiopene Derivatives in Water. Synth. Meth？1997, 84, 191–192.
[8]
Ogura, K; Nakaoka, K; Nakayama, M. Studies on Ion Transport During Potential Cycling of a Prussian Blue (Inner) Polyaniline (Outer) Bilayer Electrode by Quartz Crystal Microbalance and Fourier Transform Infrared Reflection Spectroscopy. J. Electroanal. Chem？2000, 486, 119–125.
[9]
Lupu, S; Mihailiciuc, C; Pigani, L; Renato, S; Nicolae, T; Chiara, Z. Electrochemical Preparation and Characterization of Bilayer Film Composed by Prussian Blue and Conducting Polymer. Electrochem. Commun？2002, 4, 750–758.
[10]
Xueliang, W; Tao, Y; Yuayua, F; Kui, J; Guiaun, L. A Novel Hydrogen Peroxide Biosensor Based on the Synergic Effect of Gold-Platinum Alloy Nanoparticle/Polyaniline Nanotube/Chistosan Nanocomposite Membrane. Electroanalysis？2009, 21, 819–825.
[11]
Yang, T; Zhang, W; Du, M; Jiao, K. A PDDA/Poly(2,6-pyridinedicarboxylic acid)-CNTs Composite Film DNA Electrochemical Sensor and its Application for the Detection of Specific Sequences Related to PAT Gene and NOS Gene. Talanta？2008, 75, 987–994.
[12]
Jiang, C; Yang, T; Jiao, K; Gao, H. A DNA Electrochemical Sensor with Poly-L-Lysine/Single-Walled Carbon Nanotubes Films and its Application for the Highly Sensitive EIS Detection of PAT Gene Fragment and PCR Amplification of NOS Gene. Electrochim. Acta？2008, 53, 2917–2924.
[13]
Hussain, I; Brust, M; Papworth, AJ; Cooper, AI. Preparation of Acrylate-Stabilized Gold and Silver Hydrosols and Gold-Polymer Composite Films. Langmuir？2003, 19, 4831–4835.
O’Mullane, AP; Dale, SE; Macpherson, JV; Unwin, PR. Fabrication and Electrocatalytic Properties of Polyaniline/Pt Nanoparticle Composite. Chem.Commun？2004, 14, 1606–1607.
[16]
Zhou, N; Yang, T; Jiang, C; Du, M; Jiao, K. Highly Sensitive Electrochemical Impedance Spectroscopic Detection of DNA Hybridization Based on Aunano-CNT/Pannano Films. Talanta？2009, 77, 1021–1026.
[17]
Alemán, C; Teixeira-Dias, B; Zanuy, D; Estrany, F; Armelin, E; del Valle, LJ. A Comprehensive Study of the Interactions between DNA and Poly(3,4-ethylenedioxythiophene). Polymer？2009, 50, 1965–1974.
[18]
Argun, AA; Cirpan, A; Reynolds, JR. Using Poly(3,4-ethylenedioxylthiophene) Polystyrene Sulfonate (PEDO/PSS). Adv. Mater？2003, 15, 1338–1341.
[19]
Drillet, JF; Dittmeyer, R; Juttner, K. Study of the Activity and Longterm Stability of PEDOT at Platinum Catalyst Support for the DMFC Anode. J. Appl. Electrochem？2007, 37, 1219–1226.
[20]
Dong-Hun, H; Jae-Woo, K; Su-Moon, P. Electrochemistry of Conducting Polymer 38. Electrodeposited Poly(3,4-ethylenedioxylthiophene) Studied by Current Sensing Atomic Force Micrscopy. J. Phys.Chem. B？2006, 110, 14874–14880.
[21]
Jui, HC; Chi-An, D; Wen-Yen, C. Synthensis of Highly Conductive EDOT Copolymer Film via Oxidative Chemical in situ Polymerization. J. Polym. Sci. A？2008, 46, 1662–1673.
[22]
Zotti, G; Vercelli, B; Berlin, A. Gold Nanoparticle Linking to Polypyrole and Polythiophene Monolayers and Multilayers. Chem. Mater？2008, 20, 6509–6516.
[23]
Prakash, A; Ouyang, J; Lin, JL; Yan, Y. Polymer Memory Device Based on Conjugated Polymer and Gold Nanoparticles. J Appl Phys？2006, 100, 054309:1–054309:5.
[24]
Pigani, L; Heras, A; Colina, á; Seeber, R; López-Palacios, J. Electropolymerisation of 3,4-ethylenedioxythiophene in Aqueous Solutions. Electrochem. Commun？2004, 6, 1192–1198.
[25]
Xiao, YH; Li, CM; Toh, ML; Xue, R. Adenosine 5′ Triophosphate Incorporated Poly(3,4-ethylenedioxythiophene) Modified Electrode a Bioactive Platform with Electroactivity, Stability and Biocompartibility. Chem Biol Interact？2005, 157–158, 423–426.
[26]
Balamurugan, A; Chen, S. Silver Nanograin Incorporated PEDOT Modified Electrode for Electrocatalytic Sensing of Hydrogen Peroxide. Electroanalysis？2009, 12, 1419–1423.
[27]
Zhang, Y; Zhou, JL. Occurrence and Removal of Endocrine Disrupting Chemicals in Wastewater. Chemosphere？2008, 73, 848–853.
[28]
Schilirò, T; Pignata, C; Rovere, R; Fea, E; Gilli, G. The Endocrine Disrupting Activity of Surface Waters and of Wastewater Treatment Plant Effluents in Relation to Chlorination. Chemosphere？2009, 75, 335–340.
[29]
Klaus, G; Volkmar, H; Bjoern, T; Einhard, K; Hartmut, P; Torsen, R. Endocrine Disrupting Nonylphenols Are Ubiquitous in Food. Envir. Sci. Technol？2002, 36, 1676–1680.
[30]
Zhao, JL; Ying, GG; Wang, L; Yang, JF; Yang, XB; Yang, LH; Li, X. Determination of Phenolic Endocrine Disrupting Chemicals and Acidic Pharmaceuticals in Surface Water of the Pearl Rivers in South China by Gas Chromatography-Negative Chemical Ionization-Mass Spectrometry. Sci. Total Envir？2009, 407, 962–974.
[31]
Safe, S. Endocrine Disruptors and Human Health: Is There a Problem. Toxicology？2004, 205, 3–10.
[32]
Pothitou, P; Voutsa, D. Endocrine Disrupting Compounds in Municipal and Industrial Wastewater Treatment Plants in Northern Greece. Chemosphere？2008, 73, 1716–1723.
[33]
Safe, S. Clinical Correlate of Environmental Endocrine Disruptors. Trend Endocrine Mat？2005, 16, 139–144.
[34]
Synder, SA; Westerhoff, P; Yoon, Y. Phamaceutical, Personal Care Product and Endocrine Disrupting Chemical in Water Implication for Water Industry. Environ. Eng. Sci？2003, 20, 449–469.
[35]
Jiang, JQ; Yin, Q; Zhou, JL; Pearce, P. Occurrence and Treatment Trials of Endocrine Disrupting Chemicals (Edcs) in Wastewaters. Chemosphere？2005, 61, 544–550.
[36]
Amaral Mendes, JJ. Endocrine Disrupters a Major Medical Challenge. Food Chem. Toxicol？2002, 40, 781–788.
Cheng, AKH; Sen, D; Yu, HZ. Design and Testing of Aptamer-Based Electrochemical Biosensors for Proteins and Small Molecules. Bioelectrochemistry？2009, 77, 1–12.
[39]
Li, X; Shen, L; Zhang, D; Qi, H; Gao, Q; Ma, F; Zhang, C. Electrochemical Impedance Spectroscopy for Study of Aptamer-Thrombin Interfacial Interactions. Biosen. Bioelectron？2008, 23, 1624–1630.
[40]
Kim, YS; Jung, HS; Matsuura, T; Lee, HY; Kawai, T; Gu, MB. Electrochemical Detection of 17β-estradiol Using DNA Aptamer Immobilized Gold Electrode Chip. Biosens. Bioelectron？2007, 22, 2525–2531.
[41]
Robertson, D; Tiersch, B; Kosmella, S; Koetz, J. Preparation of Crystalline Gold Nanoparticles at the Surface of Mixed Phosphatidylcholine-Ionic Surfactant Vesicles. J. Colloid Interface Sci？2007, 305, 345–351.
[42]
Vasantha, VS; Thangamuthu, R; Mingchen, S. Electrochemical Polymerization of Poly(3,4-ethylenedioxylthiophene) from Aqueous Solution Containing Hydroxyl Propyl-β-cyclodextrine and the Electrocatalytic Behavior of Modified Electrode towards Oxidation of Sulphur Oxoanion and Nitrite. Electroanalysis？2008, 20, 1754–1759.
[43]
Damlin, P; Kvarnstr？m, C; Ivaska, A. Electrochemical Synthesis and in situ Spectroelectrochemical Characterization of Poly(3,4-ethylenedioxythiophene) (PEDOT) in Room Temperature Ionic Liquids. J. Electroanal. Chem？2004, 570, 113–122.
[44]
Shin, HC; Su-Moon, P. Electrochemistry of Conductive Polymers 39. Contacts between Conducting Polymers and Noble Metal Nanoparticles Studied by Current-Sensing Atomic Force Microscopy. J. Phys. Chem. B？2006, 110, 25656–25664.
Arotiba, OA; Joseph, O; Everlyne, S; Nicolette, H; Tesfaye, W; Nazeem, J; Baker, PGL; Iwuoha, EI. An Electrochemical DNA Biosensor Developed on a Nanocomposite Platform of Gold and Poly(propyleneimine) Dendrimer. Sensors？2008, 8, 6791–6809.
[47]
Arotiba, OA; Owino, JH; Baker, PG; Iwuoha, EI. Electrochemical Impedimetry of Electrodeposited Poly(propyleneimine) Dendrimer Monolayer. J. Electroanal. Chem？2010, 638, 287–292.
[48]
Zhang, R; Di-Jin, G; Chen, D; Hu, X. Simultaneous Electrochemical Determination of Dopamine, Ascorbic Acid, and Uric Acid Using (Acid Chrome Blue K) Modified Glassy Carbon Electrode. Sens. Acuat. B？2009, 138, 174–181.
[49]
Kim, YS; Niazi, JH; Gu, MB. Specific Detection of Oxytetracycline Using DNA Aptamer-Immobilized Interdigitated Array Electrode Chip. Anal. Chim. Acta？2009, 634, 250–254.
[50]
Salci, B; Biryol, I. Voltammetric Investigation of β-estradiol. Pharmaceut. Biomed. Anal？2002, 28, 753–758.
[51]
Song, JC; Yang, J; Hu, XM. Electrochemical Determination of Estradiol Using a Poly(L-Serine) Film-Modified Electrode. J. Appl. Electrochem？2008, 38, 833–836.
[52]
Lin, XQ; Li, YX. A Sensitive Determination of Estrogens with a Pt Nano-Clusters/Multi-Walled Carbon Nanotubes Modified Glassy Carbon Electrode. Biosens. Bioelectron？2006, 22, 253–256.
