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Original Article
Label-free electrochemical aptasensor for thrombin detection with platinum nanoparticles and blocking reagent horseradish peroxidase as enhancers
Article first published online: 27 JUL 2011
DOI: 10.1002/bab.33
Copyright © 2011 International Union of Biochemistry and Molecular Biology, Inc.
Additional Information
How to Cite
Sun, T., Wang, L., Li, N. and Gan, X. (2011), Label-free electrochemical aptasensor for thrombin detection with platinum nanoparticles and blocking reagent horseradish peroxidase as enhancers. Biotechnology and Applied Biochemistry, 58: 256–260. doi: 10.1002/bab.33
Publication History
- Issue published online: 12 AUG 2011
- Article first published online: 27 JUL 2011
- Manuscript Accepted: 21 APR 2011
- Manuscript Received: 8 MAR 2011
- Abstract
- Article
- References
- Cited By
Keywords:
- blocking reagent;
- electrocatalytic amplification;
- electrochemical aptasensor;
- horseradish peroxidase;
- platinum nanoparticles
Abstract
A sensitive label-free electrochemical aptasensor was successfully fabricated for thrombin detection with platinum nanoparticles (Pt) and blocking reagent horseradish peroxidase (HRP) as enhancers. A Nafion®–graphene-coated electrode was first modified with an electrochemical probe of methylene blue (MB) through electrostatic interaction. Then Pt was electrodeposited onto an electrode for immobilization of the thrombin aptamer (TBA). Subsequently, HRP served as blocking reagent instead of bovine serum albumin (BSA). With the synergistic effect between Pt and HRP, the prepared aptasensor showed a superior catalytic efficiency toward H2O2 in the presence of MB. After the combination of target thrombin on electrode surface, the TBA–thrombin complex made a barrier for electrocatalysis of Pt and HRP and inhibited the electrotransfer, resulting in a greater decrease in MB signals. As a result, the proposed approach showed a high sensitivity and a much wider linearity to thrombin in the range from 0.005 to 50 nM with a detection limit of 1 pM.