Bouchet Aurélie, Chaix Carole, Marquette Christophe A, Blum Loïc J, Mandrand Bernard
UMR 2714 CNRS-bioMérieux, ENS, IFR 128 Biosciences Lyon Gerland, 46 Allée d'Italie, Lyon, France.
Biosens Bioelectron. 2007 Dec 15;23(5):735-40. doi: 10.1016/j.bios.2007.06.018. Epub 2007 Jul 28.
A new multidetection biosensor has been developed using the electrochemical properties of cylinder-shaped conducting polypyrrole grown on miniaturized graphite electrodes. Our objective was to conceive a sensitive, labelless and real-time DNA sensor for biomedical diagnosis. In a first step, copolymers bearing both ferrocene redox markers and oligonucleotide probes were selectively electro-addressed on microchip electrodes. Then, the study of their voltammetric response upon the addition of DNA targets revealed that the hybridization was efficiently transduced through the variation of ferrocene oxidation intensity. Using this technique, a good selectivity between Human Immunodeficiency Virus and Hepatitis B Virus targets was obtained. It was indeed possible to directly follow the hybridization. Complementary DNA detection limit reached 100 pM (3 fmol in 30 microL), which represents a good performance for such a practical, labelless and real-time sensor.
