Sequence-specific, electronic detection of oligonucleotides in blood, soil, and foodstuffs with the reagentless, reusable E-DNA sensor

Anal Chem. 2006 Aug 15;78(16):5671-7. doi: 10.1021/ac0601819.


The ability to detect specific oligonucleotides in complex, contaminant-ridden samples, without the use of exogenous reagents and using a reusable, fully electronic platform could revolutionize the detection of pathogens in the clinic and in the field. Here, we characterize a label-free, electronic sensor, termed E-DNA, for its ability to simultaneously meet these challenging demands. We find that because signal generation is coupled to a hybridization-linked conformational change, rather than to only adsorption to the sensor surface, E-DNA is selective enough to detect oligonucleotides in complex, multicomponent samples, such as blood serum and soil. Moreover, E-DNA signaling is monotonically related to target complementarity, allowing the sensor to discriminate between mismatched targets: we readily detect the complementary 17-base target against a 50 000-fold excess of genomic DNA, can distinguish a three-base mismatch from perfect target directly in blood serum, and under ideal conditions, observe statistically significant differences between single-base mismatches. Finally, because the sensing components are linked to the electrode surface, E-DNA is reusable: a 30-s room temperature wash recovers >99% of the sensor signal. This work further supports the utility of E-DNA as a rapid, specific, and convenient method for the detection of DNA and RNA sequences.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biosensing Techniques / methods*
  • DNA / chemistry*
  • Electrochemistry / methods*
  • Food Analysis*
  • Nucleic Acid Conformation*
  • Nucleic Acid Hybridization / methods*
  • Oligonucleotides / analysis*
  • Oligonucleotides / blood
  • Soil / analysis*


  • Oligonucleotides
  • Soil
  • DNA