کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5371423 1388819 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Large catalase based bioelectrode for biosensor application
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Large catalase based bioelectrode for biosensor application
چکیده انگلیسی

A large catalase (CAT) (Mr ~ 90 kDa), immobilized on multiwalled carbon nanotubes-Nafion® (MWCNT-NF) matrix and encapsulated with polyethylenimine (PEI) on glassy carbon electrode (GCE), showed a pair of nearly reversible cyclic voltammetric peaks for Fe(III)/Fe(II) couple with formal potential of about −0.45 V (vs. Ag/AgCl electrode at pH 7.5). PEI significantly reduced the charge transfer resistance and stabilized the bioelectrode through electrostatic interaction. The electron transfer rate constant and surface coverage of the immobilized CAT were 1.05 ± 0.2 s−1 and 2.1 × 10−10 mol cm−2, respectively. Studies on electrocatalytic activity and kinetics of GCE/MWCNT-NF/CAT/PEI for hydrogen peroxide (H2O2) showed the apparent Michaelis-Menten constant of 3 mM, linear response in the range of 10 μM to 5 mM, response time of ~ 2 s for steady state current, and detection limit of ~ 1 μM. A high operational and storage stability was also demonstrated for the bioelectrode. Hence, the direct electrochemistry of the large catalase and its potential biosensor application have been established through this investigation.

Graphical AbstractResearch Highlights► Direct electron tunneling between the large catalase and electrode is demonstrated. ► Polyethylenimine electrostatically stabilizes the catalase in the bioelectrode. ► The large catalase reduces overall charge transfer resistance of the bioelectrode.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biophysical Chemistry - Volume 153, Issue 1, December 2010, Pages 36-42
نویسندگان
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