title: Electrocatalytic detection of estradiol at a carbon nanotube|Ni(Cyclam) composite electrode fabricated based on a two-factorial design.
abstract: In this work, we have developed a carbon nanotube|Ni(cyclam)-coated glassy carbon electrode to achieve minimal fouling effects and to catalyse the oxidation of the oestrogen, estradiol, during voltammetric detection. This electrode was fabricated by initially applying a Nafion-carbon nanotube mixture, and then electropolymerising Ni(cyclam) complexes on the electrode. During this process, a two-level factorial design was used to optimise experimental parameters including the amount of carbon nanotubes, the concentration of Nafion and the surface coverage of Ni(cyclam). A linear calibration plot between 0.5 and 40 microM estradiol was then obtained in synthetic laboratory standard solutions. Based on a signal-to-noise ratio of 3, a detection limit of 60 nM was estimated, which is below the typical estradiol level measured in a normal menstrual cycle. The electrodes were subsequently applied to the detection of estradiol in protein-free human serum samples. Comparable sensitivity between synthetic laboratory standard solutions and serum samples was obtained, indicating minimal interference effects from the serum matrix.
authors.affiliation: Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia.
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Liu
authors.forename: Danny K Y
authors.initials: DK
authors.lastname: Wong
mesh_terms: D002384:Catalysis; D004563:Electrochemistry; D004566:Electrodes; D004958:Estradiol / Q000032:analysis* / Q000097:blood / Q000737:chemistry; D006571:Heterocyclic Compounds / Q000737:chemistry; D006801:Humans; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry; D010084:Oxidation-Reduction
chemical_list: D006571:Heterocyclic Compounds; D037742:Nanotubes, Carbon; C024560:cyclam; D004958:Estradiol; D009532:Nickel