title: Conductive architecture of Fe2O3 microspheres/self-doped polyaniline nanofibers on carbon ionic liquid electrode for impedance sensing of DNA hybridization.
abstract: A novel architecture was designed by combining the strong adsorption ability of Fe(2)O(3) microspheres to the DNA probes and excellent conductivity of self-doped polyaniline (SPAN) nanofibers (copolymer of aniline and m-aminobenzenesulfonic acid) on carbon ionic liquid electrode (CILE) for electrochemical impedance sensing of the immobilization and hybridization of DNA. The formed conductive Fe(2)O(3)/SPAN membrane on the CILE was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using [Fe(CN)(6)](3-/4-) as the indicator. The immobilization of the probe DNA on the surface of electrode and the sensitivity of DNA hybridization recognition were dramatically enhanced due to the unique synergistic effect of Fe(2)O(3) microspheres, SPAN nanofibers and ionic liquid. The DNA hybridization events were monitored with a label-free EIS strategy. Under optimal conditions, the dynamic range of this DNA biosensor for detecting the sequence-specific DNA of phosphoenolpyruvate carboxylase (PEPCase) gene from transgenically modified rape was from 1.0 x 10(-13) to 1.0 x 10(-7)mol/L, and the detection limit was 2.1 x 10(-14)mol/L. This work suggested a simple strategy to prepare a conductive interface for electrochemical detection of DNA hybridization and opened a way for the application of Fe(2)O(3) in DNA electrochemical biosensing.
authors.affiliation: Key Laboratory of Eco-chemical Engineering (Ministry of Education), College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.forename: Debao
authors.initials: D
authors.lastname: Wang
authors.forename: Kui
authors.initials: K
authors.lastname: Jiao
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D002244:Carbon / Q000737:chemistry; D004553:Electric Conductivity; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D005290:Ferric Compounds / Q000737:chemistry*; D017403:In Situ Hybridization / Q000379:methods*; D052578:Ionic Liquids / Q000737:chemistry*; D008863:Microspheres; D017422:Sequence Analysis, DNA / Q000295:instrumentation*; D014159:Transducers
chemical_list: D000814:Aniline Compounds; D005290:Ferric Compounds; D052578:Ionic Liquids; C416807:polyaniline; C000499:ferric oxide; D002244:Carbon