An RNA aptamer-based electrochemical biosensor for detection of theophylline in serum

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  • Interdisciplinary Nanoscience Center
  • Department of Chemistry
An electrochemical RNA aptamer-based biosensor for rapid and label-free detection of the bronchodilator theophylline was developed. The 5'-disulfide-functionalized end of the RNA aptamer sequence was immobilized on a gold electrode, and the 3'-amino-functionalized end was conjugated with a ferrocene (Fc) redox probe. Upon binding of theophylline the aptamer switches conformation from an open unfolded state to a closed hairpin-type conformation, resulting in the increased electron-transfer efficiency between Fc and the electrode. The electrochemical response, which was measured by differential pulse voltammetry, reaches saturation within a few minutes after addition of theophylline, and the dynamic range for detecting theophylline is 0.2-10 muM. The electrode displays an inhibited response when applied directly in serum samples treated with RNase inhibitors; however a full response to the theophylline serum concentration was obtained by transferring the electrode to blank serum-free buffer solutions. It was demonstrated that theophylline is detected with high selectivity in the presence of caffeine and theobromine.
Original languageEnglish
JournalJournal of the American Chemical Society
Pages (from-to)4256-4258
Number of pages2
Publication statusPublished - 2 Apr 2008

    Research areas

  • Aptamers, Nucleotide, Base Sequence, Biosensing Techniques, Electrochemistry, Electrodes, Gold, Humans, Sensitivity and Specificity, Surface Properties, Theophylline

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