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An enzyme-free and label-free signal-on aptasensor based on DNAzyme-driven DNA walker strategy.
- Source :
-
Analytica chimica acta [Anal Chim Acta] 2019 Nov 12; Vol. 1081, pp. 59-64. Date of Electronic Publication: 2019 Jul 10. - Publication Year :
- 2019
-
Abstract
- Herein, a signal-on electrochemical aptasensor for highly sensitive detection of thrombin (TB) was constructed based on the DNAzyme-driven DNA walker strategy. We developed a new dual functional hairpin DNA (HP) containing a substrate sequence of the Mg <superscript>2+</superscript> -dependent DNAzyme (in the loop region) and the G-quadruplex forming segment (in the stem region). The DNA walker (TBA <subscript>2</subscript> -DWs), containing a TB aptamer and an enzymatic sequence, was introduced onto gold electrode (GE) by aptamers-target specific recognition, and thus initiated the enzymatic sequences to hybridize with the substrate sequence. Then, the DNA walker could repeatedly bind and cleave HP in the assistance of Mg <superscript>2+</superscript> , unlocking many active G-quadruplex forming sequences. Finally, hemin can further bind the G-quadruplex to form G-quadruplex/hemin complexes and generate enhanced current output. The aptasensor for TB assay showed a linear detection range from 1 pM to 60000 pM with a lower detection limit of 0.58 pM. And more, the proposed detection strategy was enzyme-free and label-free.<br /> (Copyright © 2019 Elsevier B.V. All rights reserved.)
- Subjects :
- Aptamers, Nucleotide genetics
Biosensing Techniques methods
DNA genetics
DNA, Catalytic genetics
Electrochemical Techniques instrumentation
Electrochemical Techniques methods
Electrodes
G-Quadruplexes
Gold chemistry
Hemin chemistry
Inverted Repeat Sequences
Limit of Detection
Nucleic Acid Hybridization
Thrombin analysis
Aptamers, Nucleotide chemistry
DNA chemistry
DNA, Catalytic chemistry
Subjects
Details
- Language :
- English
- ISSN :
- 1873-4324
- Volume :
- 1081
- Database :
- MEDLINE
- Journal :
- Analytica chimica acta
- Publication Type :
- Academic Journal
- Accession number :
- 31446964
- Full Text :
- https://doi.org/10.1016/j.aca.2019.07.005