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Dual-readout aptasensing of antibiotic residue based on gold nanoclusters-functionalized MnO2 nanosheets with target-induced etching reaction

Abstract

This work designs a novel dual-readout biosensing protocol for quantitative or qualitative screening of antibiotic residues (Kanamycin; Kana used in the case) using spectrofluorometer and naked eyes. This assay includes two sequential reactions: target-aptamer binding to trigger Exonuclease I (Exo I)-assisted target recycling and three-way junction-assisted hybridization chain reaction (3WJ-HCR). Gold nanoclusters-functionalized manganese dioxide nanosheets (AuNCs-MnO2) were synthesized via a one-pot biomimetic mineralization process, and used as the signal-generation tags because of the quenching efficiency of MnO2 toward the AuNC's fluorescence. Upon addition of Kana analyte, target-assisted recycling and 3WJ-HCR reaction were readily implemented on functional magnetic bead, thus resulting in the assembly of numerous alkaline phosphatase (ALP) molecules through the avidin-biotin interaction, which hydrolyzed ascorbic acid 2-phosphate (AAP) to ascorbic acid (AA). The as-generated AA etched the MnO2 nanosheets into Mn2+ to release the carried AuNCs, thereby the fluorescent recovery of AuNCs. Meanwhile, a visual detection could be performed according to the change in the color of AuNCs-MnO2. Under optimum operating conditions, the intensity of fluorescence increased with the increasing Kana within a dynamic working range from 0.002 to 5 nM with a limit of detection (LOD) of 1.2 pM. A cutoff value of 50 pM Kana could be also obtained in the visual assay on the basis of the change in the color from brown to white. In addition, the precision, reproducibility and selectivity of this method were acceptable. For analysis of real milk samples with Kana, the well-matched results were acquired between the developed fluorescence assay and the referenced Kana enzyme-linked immunosorbent assay (ELISA) kit.

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Publication details

The article was received on 08 Oct 2018, accepted on 08 Nov 2018 and first published on 09 Nov 2018


Article type: Paper
DOI: 10.1039/C8TB02642D
Citation: J. Mater. Chem. B, 2018, Accepted Manuscript
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    Dual-readout aptasensing of antibiotic residue based on gold nanoclusters-functionalized MnO2 nanosheets with target-induced etching reaction

    R. Zeng, Y. Tang, L. Zhang, Z. Luo and D. Tang, J. Mater. Chem. B, 2018, Accepted Manuscript , DOI: 10.1039/C8TB02642D

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