Application of the Hybridization Chain Reaction on Electrodes for the Amplified and Parallel Electrochemical Analysis of DNA

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• 作者：Alexander Trifonov ; Etery Sharon ; Ran Tel-Vered ; Jason S. Kahn ; Itamar Willner
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：July 28, 2016
• 年：2016
• 卷：120
• 期：29
• 页码：15743-15752
• 全文大小：569K
• 年卷期：0
• ISSN：1932-7455

文摘

The hybridization chain reaction (HCR) is implemented for the development of amplified electrochemical DNA sensing platforms. The target analyte hybridizes with a probe oligonucleotide-functionalized electrode and triggers on the HCR process in the presence of the hairpins H_A and H_B. The formation of the analyte-triggered HCR chains is followed by Faradaic impedance spectroscopy or chronocoulometry using Fe(CN)₆^3–/4– or Ru(NH₃)₆³⁺ as redox labels, respectively. By using two different probe-functionalized electrodes and a mixture of four hairpins, H_A:H_B and H_C:H_D, the parallel analysis of two analytes is demonstrated. Through the structural design of the hairpin structures to include caged G-quadruplex subunits, the analyte/probe hybrid associated with the electrode triggers on the HCR process, leading to G-quadruplex-functionalized HCR chains. The association of hemin to the matrix yields electrocatalytic hemin/G-quadruplex units that provide a secondary amplification path for the detection of DNA through an electrocatalyzed reduction of H₂O₂. The system allows the detection of the analyte DNA with a detection limit corresponding to 0.2 nM.