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A novel label-free electrochemical aptasensor for thrombin based on the {nano-Au/thionine}n multilayer films as redox probes.
- Source :
-
Analytica chimica acta [Anal Chim Acta] 2010 Jun 04; Vol. 668 (2), pp. 171-6. Date of Electronic Publication: 2010 Apr 18. - Publication Year :
- 2010
-
Abstract
- Herein, a novel label-free electrochemical aptasensor based on direct immobilization of the redox probes on an electrode surface was reported. Gold electrode coated Nafion was firstly modified with redox probe-thionine (Thi) through ion exchange adsorption. Then, with the help of chemisorption and electrostatic adsorption, negatively charged nano-Au and positively charged Thi were layer-by-layer (LBL) self-assembled onto the modified electrode surface, which formed {nano-Au/Thi(+)}(n) multilayer films for improving the amount of redox probes and immobilizing thiolated thrombin aptamers (TBA). In the presence of target thrombin (TB), the TBA on the multilayer film could catch the TB onto the electrode surface, which resulted in a barrier for electro-transfer, leading to decrease of the current. The proposed method avoided the cubsome redox probe labeling process, increased the amount of redox probe and reduced the distance between the redox probe and electrode surface. Thus, the approach showed a high sensitivity and a wider linearity to TB in the range from 0.12 nM to 46 nM with a detection limit of 40 pM.<br /> (Copyright 2010 Elsevier B.V. All rights reserved.)
- Subjects :
- Animals
Aptamers, Nucleotide chemistry
Cattle
Electrochemical Techniques instrumentation
Electrochemical Techniques methods
Equipment Design methods
Gold
Metal Nanoparticles
Oxidation-Reduction
Phenothiazines
Biosensing Techniques instrumentation
Biosensing Techniques methods
Electrodes
Thrombin analysis
Subjects
Details
- Language :
- English
- ISSN :
- 1873-4324
- Volume :
- 668
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Analytica chimica acta
- Publication Type :
- Academic Journal
- Accession number :
- 20493294
- Full Text :
- https://doi.org/10.1016/j.aca.2010.04.020