An ionic liquid supported CeO<inf>2</inf>nanoshuttles-carbon nanotubes composite as a platform for impedance DNA hybridization sensing

Release time:2023-10-19 Hits:

Key Words:Single-walled carbon nanotubes (SWCN);Biosensors - Cerium oxide - Cyclic voltammetry - DNA - Electrochemical impedance spectroscopy - Genes - Glass membrane electrodes - Ionic liquids - Nanocomposites - Probes - Spectroscopy - Yarn;1-Butyl-3-methyl-imidazolium hexafluorophosphate - Carbon nanotubes composites - DNA electrochemical biosensor - Electrochemical biosensor - Electron-transfer resistance - Phosphoenolpyruvate carboxylase - Room temperature ionic liquids - Single-walled carbon nanotube (SWNTs)

Abstract:A novel nanocomposite membrane, comprising of nanosized shuttle-shaped cerium oxide (CeO<inf>2</inf>), single-walled carbon nanotubes (SWNTs) and hydrophobic room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF<inf>6</inf>), was developed on the glassy carbon electrode (GCE) for electrochemical sensing of the immobilization and hybridization of DNA. The properties of the CeO<inf>2</inf>-SWNTs-BMIMPF<inf>6</inf>/GCE, the characteristics of the immobilization and hybridization of DNA were studied by cyclic voltammetry and electrochemical impedance spectroscopy (EIS) using [Fe(CN)<inf>6</inf>]^3-/4-as the redox indicator. The synergistic effect of nano-CeO<inf>2</inf>, SWNTs and RTIL could dramatically enhance the sensitivity of DNA hybridization recognition. The electron transfer resistance (R<inf>et</inf>) of the electrode surface increased after the immobilization of probe ssDNA on the CeO<inf>2</inf>-SWNTs-BMIMPF<inf>6</inf>membrane and rose further after the hybridization of the probe ssDNA with its complementary sequence. The remarkable difference between the R<inf>et</inf>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 1.0 &times; 10^-12mol/L to 1.0 &times; 10^-7mol/L, and the detection limit was 2.3 &times; 10^-13mol/L, suggesting that the CeO<inf>2</inf>-SWNTs-BMIMPF<inf>6</inf>nanocomposite hold great promises for the applications in sensitive electrochemical biosensor. &copy; 2008 Elsevier B.V. All rights reserved.<br/>

Volume:24

Issue:8

Translation or Not:no