Electrical frequency dependent characterization of DNA hybridization

Marin Gheorghe, Anthony Guiseppi-Elie

Research output: Contribution to journalArticle

52 Scopus citations

Abstract

The hybridization of oligomeric DNA was investigated using the frequency dependent techniques of electrochemical impedance spectroscopy (EIS) and quartz crystal microgravimetry (QCM). Synthetic 5′-amino terminated single stranded oligonucleotides (ssDNA) were attached to the exposed glass surface between the digits of microlithographically fabricated interdigitated microsensor electrodes using 3-glycidoxypropyl-trimethoxysilane. Similar ssDNA immobilization was achieved to the surface of the gold driving electrodes of AT-cut quartz QCM crystals using 3-mercaptopropyl-trimethoxysilane. Significant changes in electrochemical impedance values (both real and imaginary components) (11% increase in impedance modulus at 120 Hz) and resonant frequency values (0.004% decrease) were detected as a consequence of hybridization of the bound ssDNA upon exposure to its complement under hybridization conditions. Non-complementary (random) sequence sowed a modest decrease in impedance and a non-detectable change in resonant frequency. The possibility to detect the binding state of DNA in the vicinity of an electrode, without a direct connection between the measurement electrode and the DNA, has been demonstrated. The potential for development of label-free, low density DNA microarrays is demonstrated and is being pursued.

Original languageEnglish (US)
Pages (from-to)95-102
Number of pages8
JournalBiosensors and Bioelectronics
Volume19
Issue number2
DOIs
StatePublished - Nov 15 2003

Keywords

  • DNA
  • DNA hybridization
  • Electrochemical impedance spectroscopy
  • Microarrays
  • Oligonucleotides
  • Quartz crystal microbalance
  • Silanes

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry

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