• Title of article

    Direct electrochemical probing of DNA hybridization on oligonucleotide-functionalized polypyrrole

  • Author/Authors

    Tlili، نويسنده , , Chaker and Jaffrezic-Renault، نويسنده , , Nicole J. and Martelet، نويسنده , , Claude and Korri-Youssoufi، نويسنده , , Hafsa، نويسنده ,

  • Issue Information
    روزنامه با شماره پیاپی سال 2008
  • Pages
    7
  • From page
    848
  • To page
    854
  • Abstract
    We here report a new approach for the direct label of a free detection of DNA hybridization using electrochemical techniques applied to a system made of a polypyrrole matrix supported at the surface of an electrode and modified with DNA probes by covalent grafting. The binding occurs at sites where the polypyrrole is functionalized with activated ester groups. The hybridization reactions with the DNA complementary target and non-complementary target were investigated by both amperometric analysis and non-faradaic electrochemical impedance spectroscopy. The results show a significant modification in the electrochemical response of the layer upon addition of the complementary target. A variation of the redox activity of polypyrrole was demonstrated and was shown to correlate with the result obtained with impedance measurement which was related to the modification of conjugation of the polypyrrole backbone. quist plots obtained upon hybridization reaction were analysed by the Randles circuit. Electrical parameters such as capacity and transfer charge resistance were analysed and it was shown that the hybridization reaction caused a decrease of charge transfer and an increase of capacity. The charge transfer resistance R2 showed a linear variation as a function of the complementary target concentration. The sensitivity and the detection limit were determined and raised 1 pmol which constituted a substantial enhancement when compared to the results obtained by other systems.
  • Keywords
    Label-free detection , DNA hybridization , Electrochemical detection , Impedance , charge transfer resistance , Amperometric
  • Journal title
    Materials Science and Engineering C
  • Serial Year
    2008
  • Journal title
    Materials Science and Engineering C
  • Record number

    2099474