Gold Nanoparticles Doped Conducting Polymer Nanorod Electrodes: Ferrocene Catalyzed Aptamer-Based Thrombin Immunosensor

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• 作者：Md. Aminur Rahman ; Jung Ik Son ; Mi-Sook Won ; Yoon-Bo Shim
• 刊名：Analytical Chemistry
• 出版年：2009
• 出版时间：August 15, 2009
• 年：2009
• 卷：81
• 期：16
• 页码：6604-6611
• 全文大小：300K
• 年卷期：v.81,no.16(August 15, 2009)
• ISSN：1520-6882

文摘

Au nanoparticles-doped conducting polymer nanorods electrodes (AuNPs/CPNEs) were prepared by coating Au nanorods (AuNRs) with a conducting polymer layer. The AuNRs were prepared through an electroless deposition method using the polycarbonate membrane (pore diameter, 50 nm, pore density, 6 × 10⁸ pores/cm²) as a template. The AuNPs/CPNEs combining catalytic activity of ferrocene to ascorbic acid were used for the fabrication of an ultrasensitive aptamer sensor for thrombin detection. The AuNPs/3D-CPNEs were characterized employing cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Sandwiched immunoasay for α-human thrombin with NH₂-functionalized-thrombin binding aptamer (Apt) immobilized on AuNPs/3D-CPNEs was studied through the electrocatalytic oxidation of ascorbic acid by the ferrocene moiety that was bound with an antithrombin antibody and attached with the Apt/3D-CPNEs probe through target binding. Various experimental parameters affecting thrombin detection were optimized, and the performance of the thrombin aptamer sensor was examined. The Apt/AuNPs/3D-CPNEs based thrombin sensor exhibited a wide dynamic range of 5−2000 ng L⁻¹ and a low detection limit of 5 ng L⁻¹ (0.14 pM). The selectivity and the stability of the proposed thrombin aptamer sensor were excellent, and it was tested in a real human serum sample for the detection of spiked concentrations of thrombin.