کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10639867 | 995719 | 2013 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Electrochemical behavior of ascorbate oxidase immobilized on graphite electrode modified with Au-nanoparticles
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
مواد الکترونیکی، نوری و مغناطیسی
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چکیده انگلیسی
Direct electrochemistry of ascorbate oxidase was observed when immobilized on graphite modified with nano-sized gold structures. Au-structures were electrodeposited onto the graphite surface by means of cyclic voltammetry, then the enzyme was chemisorbed onto their surface. The electron transfer between the enzyme active center and the modified electrode surface was probed by square wave voltammetry (SWV) and cyclic voltammetry (CV). The dependence of the current maxima on the scan rate was found linear, suggesting that the redox process is controlled by surface chemistry. Bioelectrocatalytic oxidation of the enzyme substrate l-ascorbic acid was explored by constant potential amperometry over the potential range from 200 to 350 mV (vs. Ag/AgCl, 3 M KCl) at the ÑÐs 5.6 and 7.0. At a potential as low as 200 mV, pH 7.0 and temperature 25 °C following operational parameters were determined for the enzyme electrode: a sensitivity: 1.54 μA mMâ1 mmâ2 (r2 = 0.995), linear dynamic range up to 3.3 mÐ, detection limit of 1.5 μÐ, response time up to 20 s.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Science and Engineering: B - Volume 178, Issue 20, 1 December 2013, Pages 1497-1502
Journal: Materials Science and Engineering: B - Volume 178, Issue 20, 1 December 2013, Pages 1497-1502
نویسندگان
Totka Dodevska, Elena Horozova, Nina Dimcheva,