title: An ionic liquid supported CeO2 nanoshuttles-carbon nanotubes composite as a platform for impedance DNA hybridization sensing.
abstract: A novel nanocomposite membrane, comprising of nanosized shuttle-shaped cerium oxide (CeO(2)), single-walled carbon nanotubes (SWNTs) and hydrophobic room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF(6)), was developed on the glassy carbon electrode (GCE) for electrochemical sensing of the immobilization and hybridization of DNA. The properties of the CeO(2)-SWNTs-BMIMPF(6)/GCE, the characteristics of the immobilization and hybridization of DNA were studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) using [Fe(CN)(6)](3-/4-) as the redox indicator. The synergistic effect of nano-CeO(2), SWNTs and RTIL could dramatically enhance the sensitivity of DNA hybridization recognition. The electron transfer resistance (R(et)) of the electrode surface increased after the immobilization of probe ssDNA on the CeO(2)-SWNTs-BMIMPF(6) membrane and rose further after the hybridization of the probe ssDNA with its complementary sequence. The remarkable difference between the R(et) value at the probe DNA-immobilized electrode and that at the hybridized electrode could be used for label-free EIS detection of the target DNA. The sequence-specific DNA of phosphoenolpyruvate carboxylase (PEPCase) gene from transgenically modified rape was detected by this DNA electrochemical biosensor. Under optimal conditions, the dynamic range for detecting the sequence-specific DNA of the PEPCase gene was from 1.0x10(-12) mol/L to 1.0x10(-7) mol/L, and the detection limit was 2.3x10(-13) mol/L, suggesting that the CeO(2)-SWNTs-BMIMPF(6) nanocomposite hold great promises for the applications in sensitive electrochemical biosensor.
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: Xuming
authors.initials: X
authors.lastname: Zhuang
authors.forename: Zhiyan
authors.initials: Z
authors.lastname: Guo
authors.forename: Kui
authors.initials: K
authors.lastname: Jiao
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000295:instrumentation*; D002563:Cerium / Q000737:chemistry*; D017076:Computer-Aided Design; D004247:DNA / Q000032:analysis / Q000235:genetics*; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017403:In Situ Hybridization / Q000295:instrumentation*; D052578:Ionic Liquids / Q000737:chemistry; D008969:Molecular Sequence Data; D036103:Nanotechnology / Q000295:instrumentation; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000295:instrumentation*
chemical_list: D052578:Ionic Liquids; D037742:Nanotubes, Carbon; D002563:Cerium; C030583:ceric oxide; D004247:DNA