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- Title
A triply amplified electrochemical lead(II) sensor by using a DNAzyme and via formation of a DNA-gold nanoparticle network induced by a catalytic hairpin assembly.
- Authors
Song, Xiaolei; Wang, Yu; Liu, Su; Zhang, Xue; Wang, Jingfeng; Wang, Haiwang; Zhang, Fenfen; Yu, Jinghua; Huang, Jiadong
- Abstract
An amplified electrochemical biosensing scheme is described for lead(II) ions. It is making use of DNAzyme-assisted target recycling and catalytic hairpin assembly (CHA). The hairpin strand (substrate probe for the Pb2+-based DNAzyme; referred to as SP) is composed of trigger probe (TP) and a capture probe 1 attached to gold nanoparticles (AuNP). In the presence of the enzyme probe that partially hybridizes with SP, the introduction of Pb2+ triggers target recycling and drives the highly amplified translation of target Pb(II) to TP. The CHA reaction is further initiated by TP. The modified AuNP act as the connecting unit, and this leads to the formation of a 3D DNA-AuNP network on the electrode (which is the third amplification step). It can bind the positively charged redox mediator RuHex via electrostatic interaction for electrochemical detection. This biosensor has a low detection limit (95 pM) and any analytical range that covers the 100 pM to 5 μM Pb(II) concentration range. It is selective over other divalent metal ions. It was applied to the determination of Pb2+ in spiked real-world samples.
- Subjects
HAIRPIN (Genetics); GOLD nanoparticles; ELECTROSTATIC interaction; METAL ions; DETECTION limit; EXONUCLEASES; DNA synthesis
- Publication
Microchimica Acta, 2019, Vol 186, Issue 8, pN.PAG
- ISSN
0026-3672
- Publication type
Article
- DOI
10.1007/s00604-019-3612-5