Highly Sensitive and Selective Copper (II)-Catalyzed Dual-DNAzyme Colorimetric Biosensor Based on Exonuclease III-Mediated Cyclical Assembly
“Cu-DNAzyme” and “G4-DNAzyme” were used to develop a “turn-off” dual-DNAzyme colorimetric biosensor, which could be used to detect Cu<sup>2+</sup> by employing exonuclease III-mediated cyclical assembly (EMCA). EMCA was based on the cleavage activity of Cu<sup>2+</sup> to tra...
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| Auteurs principaux: | , , , , |
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| Format: | article |
| Langue: | EN |
| Publié: |
MDPI AG
2021
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| Sujets: | |
| Accès en ligne: | https://doaj.org/article/dcad7dc5a1b74831aacaaf4fe6762833 |
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| Résumé: | “Cu-DNAzyme” and “G4-DNAzyme” were used to develop a “turn-off” dual-DNAzyme colorimetric biosensor, which could be used to detect Cu<sup>2+</sup> by employing exonuclease III-mediated cyclical assembly (EMCA). EMCA was based on the cleavage activity of Cu<sup>2+</sup> to transfer the linkage sequences of the substrate strand and enzyme strand into the transition sequence. The horseradish peroxidase (HRP)-mimicking activity of the G4-DNAzyme was lost after binding with the complementary transition sequence and was hydrolyzed by <i><b>Exo</b></i> III. These results demonstrate that the proposed colorimetric biosensor was an effective method for ultradetection of trace metals in a high original signal background. Due to the high sensitivity of the biosensor, the limit of detection (LOD) of Cu<sup>2+</sup> is 0.16 nM. This design offers a general purpose platform that could be applied for the detection of any metal ion target through adjustment of metal-dependent DNA-cleaving DNAzymes, which is of great significance for the rapid determination of food safety. |
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