title: Sequence-specific, electronic detection of oligonucleotides in blood, soil, and foodstuffs with the reagentless, reusable E-DNA sensor.
abstract: 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.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA.
authors.forename: Arica A
authors.initials: AA
authors.lastname: Lubin
authors.forename: Rebecca Y
authors.initials: RY
authors.lastname: Lai
authors.forename: Brian R
authors.initials: BR
authors.lastname: Baker
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Heeger
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Plaxco
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D005504:Food Analysis; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization / Q000379:methods*; D009841:Oligonucleotides / Q000032:analysis* / Q000097:blood; D012987:Soil / Q000032:analysis*
chemical_list: D009841:Oligonucleotides; D012987:Soil; D004247:DNA