title: Amperometric determination of bovine insulin based on synergic action of carbon nanotubes and cobalt hexacyanoferrate nanoparticles stabilized by EDTA.
abstract: A simple approach is proposed for the synthesis of cobalt hexacyanoferrate nanoparticles (CoNPs) with uniform shape and size controlled by ethylene diamine tetraacetic acid (EDTA) as a stabilizer. A sensitive amperometric biosensor for insulin has been prepared using glassy carbon electrodes by solubilization of carbon nanotubes (CNTs) in chitosan (CHIT) together with CoNPs synthesized by the new methodology. The CoNP-CNT-CHIT organic-inorganic system exerts a synergistic effect, resulting in the remarkably enhanced insulin currents owing to the superior electron-transfer ability of CNTs and the excellent reversible redox centers of CoNPs. High-resolution transmission electron microscopy (HRTEM) was used to provide closer inspection of the CoNPs. The effects of alkali metal cations and the concentrations of CNTs and CoNPs on the voltammetric behavior of the film-modified electrode were also investigated. In pH 6.98 phosphate buffer (PB) at +0.7 V (vs. SCE) the insulin biosensor exhibits a linear response range of 0.1-3 microM with a correlation coefficient of 0.98, and the detection limit (S/N=3) is determined to be 40 nM, the stability of the biosensor was tested and found satisfactory. There is great promise for in vivo measurements of this important hormone.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's Republic of China.
authors.forename: Fengli
authors.initials: F
authors.lastname: Qu
authors.forename: Minghui
authors.initials: M
authors.lastname: Yang
authors.forename: Yashuang
authors.initials: Y
authors.lastname: Lu
authors.forename: Guoli
authors.initials: G
authors.lastname: Shen
authors.forename: Ruqin
authors.initials: R
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002412:Cations; D004492:Edetic Acid / Q000737:chemistry*; D004563:Electrochemistry; D004579:Electron Transport; D005295:Ferrocyanides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000032:analysis*; D008672:Metals, Alkali / Q000737:chemistry; D008839:Microelectrodes; D046529:Microscopy, Electron, Transmission / Q000379:methods; D008969:Molecular Sequence Data; D053758:Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010084:Oxidation-Reduction
chemical_list: D002412:Cations; D005295:Ferrocyanides; D007328:Insulin; D008672:Metals, Alkali; D037742:Nanotubes, Carbon; C116383:ferrocyn; D004492:Edetic Acid