Electrochemical detection of DNA hybridization amplified by nanoparticles. Biosensors & bioelectronics

Hui Peng, Christian Soeller, Mark B Cannell, Graham A Bowmaker, Ralph P Cooney, Jadranka Travas-Sejdic

Research output: Contribution to journalArticle (Academic Journal)peer-review

100 Citations (Scopus)


Detection of specific oligonucleotide (ODN) fragments has become an important field in many areas of biomedicine. We describe a novel ODN sensor based on electropolymerization of a conducting polymer (polypyrrole) in the presence of a sample containing ODN(s). The resulting trapped ODN(s) are then probed by addition of complimentary sequence ODN. By incorporating CdS nanoparticles with the probe, a significant improvement in sensor sensitivity was observed. Impedance spectroscopy suggested that optimal detection of hybridization occurred at frequencies>or=3000 Hz (for a 0.07 cm2 85 nm thick film). At these frequencies, the impedance signal was almost linear with the logarithm of ODN concentration in the range 3.7-370 nM with a detection limit of approximately 1 nM ODN (for the sensor fabricated). Importantly, the sensor could be regenerated by removing hybridized ODN with NaOH suggesting possibility of the sensor re-use.
Original languageEnglish
Pages (from-to)1727-1736
Number of pages10
JournalBiosens Bioelectron
Issue number9
Publication statusPublished - 15 Jan 2006


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