title: A simple gold plate electrode modified with Gd-doped TiO₂ nanoparticles used for determination of trace nitrite in cured food.
abstract: A simple gold plate electrode (GPE) based on a gadolinium-doped titanium dioxide (Gd/TiO₂) ultrathin film was successfully constructed by using a surface sol-gel technique, and used for the detection of trace amounts of nitrite in cured foods. The Gd/TiO₂ nanoparticles were synthesised and characterised via scanning electron microscopy (SEM) and X-ray diffraction (XRD), indicating that the Gd-doped TiO₂ formed an anatase phase through roasting at 450°C, generating actively interstitial oxygen at the interface of the surface of TiO₂ lattice surrounded by Gd³⁺. The electro-catalytic effect for oxidation of nitrite on the modified electrode was investigated by cyclic voltammetry in 0.10 mol l⁻¹ sulfuric acid media solution, showing that the modified electrode exhibited excellent response performance to nitrite with good reproducibility, selectivity and stability. The catalytic peak current was found to be linear with nitrite concentrations in the range of 8.0 × 10⁻⁷ to 4.0 × 10⁻⁴) mol l⁻¹, with a detection limit of 5.0 × 10⁻⁷ mol l⁻¹ (S/N = 3). The modified electrode could be used for the determination of nitrite in the cured sausage samples with a satisfactory recovery in the range of 95.5-104%, showing its promising application for food safety monitoring.
authors.affiliation: Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha, China.
authors.forename: M-L
authors.initials: ML
authors.lastname: Zhang
authors.forename: Z
authors.initials: Z
authors.lastname: Cao
authors.forename: J-L
authors.initials: JL
authors.lastname: He
authors.forename: L
authors.initials: L
authors.lastname: Xue
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
authors.forename: S
authors.initials: S
authors.lastname: Long
authors.forename: T
authors.initials: T
authors.lastname: Deng
authors.forename: L
authors.initials: L
authors.lastname: Zhang
mesh_terms: D002273:Carcinogens / Q000032:analysis*; D002681:China; D004566:Electrodes; D005506:Food Contamination; D005513:Food Inspection / Q000295:instrumentation*; D057141:Food, Preserved / Q000032:analysis*; D005682:Gadolinium / Q000737:chemistry; D006046:Gold; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D008422:Materials Testing; D008461:Meat Products / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D036103:Nanotechnology; D009573:Nitrites / Q000032:analysis*; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D002273:Carcinogens; D009573:Nitrites; C009495:titanium dioxide; D006046:Gold; D005682:Gadolinium; D014025:Titanium