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Electrochemical current rectification–a novel signal amplification strategy for highly sensitive and selective aptamer-based biosensor
- Source :
- Biosensors and Bioelectronics. 66:62-68
- Publication Year :
- 2015
- Publisher :
- Elsevier BV, 2015.
-
Abstract
- Electrochemical aptamer-based (E-AB) sensors represent an emerging class of recently developed sensors. However, numerous of these sensors are limited by a low surface density of electrode-bound redox-oligonucleotides which are used as probe. Here we propose to use the concept of electrochemical current rectification (ECR) for the enhancement of the redox signal of E-AB sensors. Commonly, the probe-DNA performs a change in conformation during target binding and enables a nonrecurring charge transfer between redox-tag and electrode. In our system, the redox-tag of the probe-DNA is continuously replenished by solution-phase redox molecules. A unidirectional electron transfer from electrode via surface-linked redox-tag to the solution-phase redox molecules arises that efficiently amplifies the current response. Using this robust and straight-forward strategy, the developed sensor showed a substantial signal amplification and consequently improved sensitivity with a calculated detection limit of 114nM for ATP, which was improved by one order of magnitude compared with the amplification-free detection and superior to other previous detection results using enzymes or nanomaterials-based signal amplification. To the best of our knowledge, this is the first demonstration of an aptamer-based electrochemical biosensor involving electrochemical rectification, which can be presumably transferred to other biomedical sensor systems.
- Subjects :
- Materials science
Aptamer
Biomedical Engineering
Biophysics
Nanotechnology
Biosensing Techniques
Redox
Signal
Electron transfer
Adenosine Triphosphate
Rectification
Limit of Detection
Electrochemistry
Animals
Electrodes
Detection limit
Base Sequence
Electrochemical Techniques
Equipment Design
General Medicine
Aptamers, Nucleotide
Electrode
Cattle
Gold
Oxidation-Reduction
Biosensor
Biotechnology
Subjects
Details
- ISSN :
- 09565663
- Volume :
- 66
- Database :
- OpenAIRE
- Journal :
- Biosensors and Bioelectronics
- Accession number :
- edsair.doi.dedup.....e7ae256c6474a02a68e7d98544ee2ad5