title: Effect of the size of electrode on electrochemical properties of ferrocene-functionalized polypyrrole towards DNA sensing.
abstract: A simple and highly sensitive electrochemical DNA sensor based on a ferrocene-functionalized polypyrrole has been prepared on a microelectrode array substrate for a multi-DNA detection chip format. A copolymer formed with 1-(phthalimidylbutanoate)-1'-(N-(3-butylpyrrole)butanamide)ferrocene (Py-Fe-NHP) and pyrrole was electrocopolymerized on the gold surface of both macroelectrode and biochip formats. DNA probes bearing an amino group were covalently grafted by substitution of NHP groups and the hybridization reaction was followed by monitoring the redox signal of the ferrocenyl group acting as the probe. The integration of the polymers into chip format produces high-density arrays of individually addressable oligonucleotide microelectrodes. Results show that reducing the size of the electrodes from a macroelectrode to the chip format allows a variation of the nucleation and the growth process during electropolymerization of modified pyrrole monomers. These modifications enable an increase in the sensitivity and selectivity of DNA hybridization.
authors.affiliation: Equipe de Chimie Bioorganique et Bioinorganique, CNRS UMR 8182, Institut de Chimie Moléculaire et de Matériaux d'Orsay, Université Paris-Sud, Bâtiment 420, Orsay, France.
authors.forename: H Q A
authors.initials: HQ
authors.lastname: Lê
authors.forename: S
authors.initials: S
authors.lastname: Chebil
authors.forename: B
authors.initials: B
authors.lastname: Makrouf
authors.forename: H
authors.initials: H
authors.lastname: Sauriat-Dorizon
authors.forename: B
authors.initials: B
authors.lastname: Mandrand
authors.forename: H
authors.initials: H
authors.lastname: Korri-Youssoufi
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D005296:Ferrous Compounds / Q000737:chemistry*; D000075163:Metallocenes; D008855:Microscopy, Electron, Scanning / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D008956:Models, Chemical; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*
chemical_list: D005296:Ferrous Compounds; D000075163:Metallocenes; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D004247:DNA; C004998:ferrocene