Highly sensitive fluorescence detection of mercury (II) ions based on WS2 nanosheets and T7 exonuclease assisted cyclic enzymatic amplification
| Autor: | Dong-Mei Bai, Ya-Hui Du, Zhaohui Li, Jia Ge, Danyang Ji, Xin-Geng, Lin Zhang, Jia-Jia Chen, Yalei Hu |
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| Rok vydání: | 2017 |
| Předmět: |
Fluorophore
Base pair Metal ions in aqueous solution Analytical chemistry 02 engineering and technology 010402 general chemistry Photochemistry 01 natural sciences chemistry.chemical_compound Materials Chemistry Electrical and Electronic Engineering Instrumentation Nanosheet Detection limit Nuclease biology Oligonucleotide Metals and Alloys 021001 nanoscience & nanotechnology Condensed Matter Physics Fluorescence 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry biology.protein 0210 nano-technology |
| Zdroj: | Sensors and Actuators B: Chemical. 249:189-194 |
| ISSN: | 0925-4005 |
| DOI: | 10.1016/j.snb.2017.04.094 |
| Popis: | In this work, a simple and signal-on assay has been developed for highly sensitive and selective detection of mercury ion (Hg 2+ ) based on the WS 2 nanosheets and T7 exonuclease-assisted cyclic signal amplification. WS 2 nanosheet exhibits differential affinity toward short oligonucleotide fragment versus single-stranded DNA (ssDNA) probe, which is used as an adsorption material for capturing ssDNA and an efficient fluorescence quencher for reducing the background signal. T7 exonuclease, a sequence independent nuclease, catalyzes the removal of 5′ mononucleotides from the 5′ termini of double stranded DNA, while its activity on ssDNA is limited. Without Hg 2+ , FAM-labelled ssDNA probe and target probe are adsorbed by the WS 2 nanosheet and the fluorescence of FAM-labelled signal probe is quenched. In the presence of Hg 2+ , a FAM-labelled ssDNA probe could hybridize with the target probe to form duplex structures with a blunt 5′-terminal of signal probe through the formation of T-Hg 2+ -T base pairing. The FAM-labelled signal probe with a blunt 5′-terminal in the formed duplex can be digested by T7 exonuclease in the direction from 5′ to 3′, liberating the FAM fluorophore and releasing the Hg 2+ . The released target Hg 2+ and the remaining probe then bind another FAM-labelled ssDNA, and initiate the next round of cleavage, resulting in the release of numerous FAM labels back into the solution and significantly amplified fluorescent signal. This approach can warrant the detection limit for Hg 2+ down to 0.1 nM (S/N = 3) with high selectivity against other metal ions. Moreover, the application of the sensor for lake water shows that the proposed method works well for real samples. This research demonstrates an alternative approach to detect targets of interest that holds high prospects for detecting other biomolecules or metal ions in the near future. |
| Databáze: | OpenAIRE |
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