Rapid, sequence-specific detection of unpurified PCR amplicons via a reusable, electrochemical sensor
- Rebecca Y. Lai*,†,‡,
- Eric T. Lagally§,
- Sang-Ho Lee§,
- H. T. Soh§,¶,‖,
- Kevin W. Plaxco*,†,§,**, and
- Alan J. Heeger*,†,‡,‖,**
- *Center for Polymers and Organic Solids, Departments of
- †Chemistry and Biochemistry,
- ‡Physics, and
- ¶Mechanical Engineering,
- §Biomolecular Science and Engineering Program, and
- ‖Materials Department, University of California, Santa Barbara, CA 93106
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Contributed by Alan J. Heeger, January 3, 2006
Abstract
We report an electrochemical method for the sequence-specific detection of unpurified amplification products of the gyrB gene of Salmonella typhimurium. Using an asymmetric PCR and the electrochemical E-DNA detection scheme, single-stranded amplicons were produced from as few as 90 gene copies and, without subsequent purification, rapidly identified. The detection is specific; the sensor does not respond when challenged with control oligonucleotides based on the gyrB genes of either Escherichia coli or various Shigella species. In contrast to existing sequence-specific optical- and capillary electrophoresis-based detection methods, the E-DNA sensor is fully electronic and requires neither cumbersome, expensive optics nor high voltage power supplies. Given these advantages, E-DNA sensors appear well suited for implementation in portable PCR microdevices directed at, for example, the rapid detection of pathogens.
Footnotes
- **To whom correspondence may be addressed. E-mail: kwp{at}chem.ucsb.edu or ajhe{at}physics.ucsb.edu
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Author contributions: R.Y.L., E.T.L., and K.W.P. designed research; R.Y.L., E.T.L., and S.-H.L. performed research; R.Y.L. and E.T.L. analyzed data; and R.Y.L., E.T.L., H.T.S., K.W.P., and A.J.H. wrote the paper.
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Conflict of interest statement: No conflicts declared.
- Abbreviation:
- MB,
- methylene blue
- © 2006 by The National Academy of Sciences of the USA
