کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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221325 | 463385 | 2006 | 10 صفحه PDF | دانلود رایگان |
Microelectrode sensors for phenol and catechol are described, based on the sequential immobilization of polystyrene sulphonate, polyallylamine, tyrosinase and polyallylamine again, onto micrometer scale latex spheres, followed by the adsorption of the spheres onto electrochemically pretreated carbon fibres. The steady state responses of the fibres are analyzed in terms of a cylindrical diffusion – kinetic model. It is deduced that the adsorbed latex particles provide a relatively open film structure, resulting in a diffusion coefficient only one order of magnitude lower than the solution value, and that at minimum 2–3% of the immobilized enzyme is catalytically active. The optimised sensors exhibit linear ranges to phenol and catechol of 7–56.5 μM and 2–19.7 μM respectively, with sensitivities of 0.15 A M−1 cm−2 and 1.72 A M−1 cm−2 respectively. The limiting factor to sensor stability is desorption of latex from the fibres.
Journal: Journal of Electroanalytical Chemistry - Volume 589, Issue 2, 15 April 2006, Pages 249–258