Screening and identification of nucleic acid aptamers for the detection of dinotefuran residues

The extensive use of dinotefuran poses potential risks to the safety of agricultural products and the ecological environment. Therefore, rapid and accurate detection of dinotefuran residues is of great significance. In this study, nucleic acid aptamers Seq1, Seq12, and Seq14 for dinotefuran were screened and obtained from ssDNA (single-stranded DNA) random library through graphene oxide-systematic evolution of ligands by exponential enrichment (GO-SELEX) technology. The secondary structure of the aptamer was predicted and the affinity of the aptamer was detected. The dissociation constants of the aptamer Seq1, Seq12 and Seq14 were 164.23 ± 25.41 nmol/L, 201.68 ± 17.42 nmol/L and 237.10 ± 29.17 nmol/L, respectively. A colorimetric detection method was established using aptamer Seq1 and gold nanoparticles (AuNPs). The limit of detection (LOD) was estimated to be 0.002 mg/kg. Compared with traditional detection methods, the AuNPs colorimetric detection method established with GO-SELEX in this study can achieve more rapid and convenient on-site detection, and it has great application potential in agricultural production practices that emphasize timeliness and freshness.