Shipin Kexue (Feb 2023)

A Fluorescent Aptasensor Based on Fe3+ Doped Polydopamine Nanospheres for Detection of Deoxynivalenol in Wheat

  • LU Nian, MA Ji,, CHENG Junhu, SUN Da-wen

DOI
https://doi.org/10.7506/spkx1002-6630-20220228-241
Journal volume & issue
Vol. 44, no. 4
pp. 313 – 320

Abstract

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Objective: A fluorescent aptasensor based on fluorescence resonance energy transfer (FRET) was constructed for the detection of deoxynivalenol (DON) in wheat. The ability of polydopamine nanospheres (PDANS) in the sensor to quench 6-carboxyuorescein (FAM) was improved by doping with Fe3+. Methods: FAM labeled DON aptamer (PDON) was adsorbed on the surface of PDANS (Fe-PDANS) doped with Fe3+ via π-π stacking non-covalent interactions, and Fe-PDANS quenched the fluorescence of FAM through FRET. In the presence of DON, PDON could specifically combine with DON, changing the conformation of PDON, making it difficult to adsorb onto Fe-PDANS, and finally enhancing the fluorescence signal of the sensor for the detection of DON. Results: The aptasensor exhibited a linear range from 0.266 7 to 133.3 ng/mL for DON, and the detection limit was 0.118 2 ng/mL. The results of this aptasensor for DON in positive wheat samples were not significantly different (P > 0.05) from those obtained by enzyme-linked immunosorbent assay (ELISA). Conclusion: The fluorescent aptasensor is characterized by rapid detection, excellent sensitivity, high specificity and good repeatability, which will provide a new method for the detection of DON in wheat.

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