title: DNA electrochemical sensor based on conducting polymer: dependence of the "signal-on" detection on the probe sequence localization.
abstract: We show in this work that it is possible to make selective direct electrochemical hybridization detection of a target strand onto a probe strand immobilized on a conducting polymer modified with a quinone group, which presents cation-exchange properties. This leads to a "signal-on"detection, a unique behavior in comparison to similar systems described in the literature. It is shown that this system is efficient for various probe and target lengths (10-30 bp) and can discriminate a single mismatch. To go further in comprehension of the detection mechanism, a systematic study of the electrochemical response versus the probe sequence localization onto the immobilized strand is performed. For example, a 30-bp target strand is divided into three shorter 10-bp sequences (A-C, respectively), and we investigate the successive hybridization of these 1/3 strands onto the 30-bp probe strand. It is shown that one probe strand can be used to address several shorter targets.
authors.affiliation: Laboratoire Interfaces-Traitements-Organisation et Dynamique des Systèmes (ITODYS), Université Paris 7-Denis Diderot, associé au CNRS, UMR 7086, 1, rue Guy de la Brosse, 75005 Paris, France.
authors.forename: Steeve
authors.initials: S
authors.lastname: Reisberg
authors.forename: Benoît
authors.initials: B
authors.lastname: Piro
authors.forename: Vincent
authors.initials: V
authors.lastname: Noël
authors.forename: Minh Chau
authors.initials: MC
authors.lastname: Pham
mesh_terms: D020029:Base Pairing; D001483:Base Sequence; D016227:Benzoquinones / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D015342:DNA Probes / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods*; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D016227:Benzoquinones; D015342:DNA Probes; D011108:Polymers; C004532:quinone