title: Electrochemical current rectification-a novel signal amplification strategy for highly sensitive and selective aptamer-based biosensor.
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.
authors.affiliation: Peter-Grünberg-Institute, PGI-8, Research Center Jülich, JARA-Fundamentals of Future Information Technology, Jülich 52425, Germany.
authors.forename: Lingyan
authors.initials: L
authors.lastname: Feng
authors.affiliation: Peter-Grünberg-Institute, PGI-8, Research Center Jülich, JARA-Fundamentals of Future Information Technology, Jülich 52425, Germany.
authors.forename: Arumugam
authors.initials: A
authors.lastname: Sivanesan
authors.affiliation: Peter-Grünberg-Institute, PGI-8, Research Center Jülich, JARA-Fundamentals of Future Information Technology, Jülich 52425, Germany.
authors.forename: Zhaozi
authors.initials: Z
authors.lastname: Lyu
authors.affiliation: Peter-Grünberg-Institute, PGI-8, Research Center Jülich, JARA-Fundamentals of Future Information Technology, Jülich 52425, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Offenhäusser
authors.affiliation: Peter-Grünberg-Institute, PGI-8, Research Center Jülich, JARA-Fundamentals of Future Information Technology, Jülich 52425, Germany. Electronic address: dirk.mayer@fz-juelich.de.
authors.forename: Dirk
authors.initials: D
authors.lastname: Mayer
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis / Q000097:blood*; D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004867:Equipment Design; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D010084:Oxidation-Reduction
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D000255:Adenosine Triphosphate
keywords: Aptamer; Electrochemical biosensor; Electrochemical current rectification; Signal amplification