کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
869370 909829 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Electrochemical impedance spectroscopy for study of aptamer–thrombin interfacial interactions
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Electrochemical impedance spectroscopy for study of aptamer–thrombin interfacial interactions
چکیده انگلیسی

A simple and highly sensitive electrochemical impedance spectroscopy (EIS) biosensor based on a thrombin-binding aptamer as molecular recognition element was developed for the determination of thrombin. The signal enhancement was achieved by using gold nanoparticles (GNPs), which was electrodeposited onto a glassy carbon electrode (GCE), as a platform for the immobilization of the thiolated aptamer. In the measurement of thrombin, the change in interfacial electron transfer resistance of the biosensor using a redox couple of [Fe(CN)6]3−/4− as the probe was monitored. The increase of the electron transfer resistance of the biosensor is linear with the concentration of thrombin in the range from 0.12 nM to 30 nM. The association and dissociation rate constants of the immobilized aptamer–thrombin complex were 6.7 × 103 M−1 s−1 and 1.0 × 10−4 s−1, respectively. The association and dissociation constants of three different immobilized aptamers binding with thrombin were measured and the difference of the dissociation constants obtained was discussed. This work demonstrates that GNPs electrodeposited on GCE used as a platform for the immobilization of the thiolated aptamer can improve the sensitivity of an EIS biosensor for the determination of protein. This work also demonstrates that EIS method is an efficient method for the determination of association and dissociation constants on GNPs modified GCE.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biosensors and Bioelectronics - Volume 23, Issue 11, 15 June 2008, Pages 1624–1630
نویسندگان
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