4 results about "Okadaic acid" patented technology

The invention discloses light-driven toxin-enriched composite hydrogel as well as a preparation method and application thereof. The composite hydrogel comprises light-driven hydrogel and detection hydrogel, the light-driven hydrogel is agarose hydrogel doped with Au (at) Ag core-shell nano particles; the detection hydrogel is a double strand formed by an okadaic acid aptamer and a complementary sequence cDNA thereof, and a double strand formed by a domoic acid aptamer and a complementary sequence DNAzyme thereof, the hairpin H1 is used for modifying a quenching group BHQ2 at the 3'end, the hairpin H2 is used for modifying a fluorophore Cy3 at the neck part, the hairpin H3 is used for modifying a fluorophore FAM and a quenching group BHQ1 at the two ends respectively, and the metal ion doped agarose hydrogel is used for catalyzing DNAzyme cyclic shearing; and the photo-thermal driving unit is positioned on the detection function unit. According to the present invention, with the composite system of upper layer photo-thermal enrichment and lower layer dual-signal detection, the rapid and high-sensitivity simultaneous detection of the okadaic acid and the domoic acid is achieved through the combination of the photo-thermal transpiration effect and the HCR and DNAzyme cyclic shearing reaction;

The invention discloses a divalent nucleic acid aptamer fluorescence detection method based on an exonuclease I auxiliary target circulation strategy, and belongs to the field of analysis and detection.The divalent nucleic acid aptamer is a repetitive sequence composed of two monovalent nucleic acid aptamers and can form double-stranded DNA through base complementary pairing with complementary strand cDNA of the divalent nucleic acid aptamer, and the divalent nucleic acid aptamer can be used for fluorescence detection of the divalent nucleic acid aptamer. The method comprises the following steps: taking a bivalent nucleic acid aptamer as a template, forming a DNA silver nanocluster (DNA-AgNCs) under the action of silver nitrate and sodium borohydride, and when the target okadaic acid exists, combining the bivalent nucleic acid aptamer with the target, so that cDNA can be replaced from double-stranded DNA by the target. Exonuclease I is added to perform enzyme digestion on the cDNA and the divalent nucleic acid aptamer, so that the fluorescence intensity of the DNA-AgNCs can be rapidly reduced. The content of the okadaic acid can be judged by detecting the change of the fluorescence intensity. The invention provides a simple, convenient, rapid, high-sensitivity and high-specificity detection method for okadaic acid detection based on a divalent nucleic acid aptamer for the first time.

The invention relates to an okadaic acid mimic epitope peptide and application. The amino acid sequence of the okadaic acid mimic epitope peptide is shown as SEQ ID NO: 1, 3, 5, 7, 9, 11, 13 or 15. The mimic epitope peptide can be specifically combined with an okadaic acid antibody, and a sensitive and rapid competitive enzyme-linked immunosorbent assay is established by using the phage for displaying the mimic epitope peptide; according to the method, the IC50 is 0.83 ng / mL, the LOD is 0.21 ng / mL, and the detection range is 0.35 to 1.98 ng / mL; the competitive immunoassay method established on the basis of the mimic epitope peptide provided by the invention is more sensitive than the traditional immunoassay method, has good cross reaction to other marine toxins, avoids the use of toxin antigens, and is green and environment-friendly.

This invention discloses a microporous organic network hollow fiber membrane for efficient extraction of okadaic acid and its applications, belonging to the field of marine food safety detection technology. The fiber membrane is prepared by a combination of electrospinning, in-situ growth, and sacrificial template methods. This fiber membrane possesses a hollow fiber structure, high stability, and high extraction efficiency, and can be applied to the efficient extraction of trace amounts of okadaic acid from shellfish samples. Furthermore, by coupling it with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS / MS), rapid and accurate detection of okadaic acid in shellfish samples can be achieved, demonstrating broad application prospects in the field of aquatic food safety screening.