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An enzyme-free and label-free signal-on aptasensor based on DNAzyme-driven DNA walker strategy.
- Source :
-
Analytica Chimica Acta . Nov2019, Vol. 1081, p59-64. 6p. - 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 Mg2+-dependent DNAzyme (in the loop region) and the G-quadruplex forming segment (in the stem region). The DNA walker (TBA 2 -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 Mg2+, 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. Image 1 • A signal-on electrochemical aptasensor based on DNAzyme-driven DNA Walker strategy has been developed. • DNA walker is driven by DNAzyme and induced by dual recognition of target molecules. • A new dual functional hairpin DNA (HP) was developed and used in this electrochemical anpptsensor. • A signal-on electrochemical aptasensor is designed from enzyme-free and label-free. [ABSTRACT FROM AUTHOR]
- Subjects :
- *APTAMERS
*DNA
*GOLD electrodes
*DETECTION limit
*HEMIN
Subjects
Details
- Language :
- English
- ISSN :
- 00032670
- Volume :
- 1081
- Database :
- Academic Search Index
- Journal :
- Analytica Chimica Acta
- Publication Type :
- Academic Journal
- Accession number :
- 138179032
- Full Text :
- https://doi.org/10.1016/j.aca.2019.07.005