Nucleic acid aptamer for specifically identifying ochratoxin A and preparation method thereof

Abstract

The invention relates to a nucleic acid aptamer for specifically identifying ochratoxin A and a preparation method thereof. The sequence of the single-chain DNA (deoxyribonucleic acid) aptamer is a sequence I. The nucleic acid aptamer for specifically identifying the ochratoxin A is characterized in that by adopting the index enrichment ligand system advancing technology based on graphene oxide separation, and in-vitro screening, the single-chain oligonucleotide aptamer with high affinity and ability of specifically identifying the OTA toxin is obtained; the specificity is good, the stability is high, the cost is low, the synthesizing and modifying are easy, the convenience in use is realized, the toxicity is avoided, and the like; the nucleic acid aptamer can be applied to studying of biological sensors and solid-phase affinity purifying columns based on the nucleic acid aptamer, and analyzing methods for quick detection on agricultural products, and the like.

Description

technical field [0001] The invention belongs to the field of biotechnology, and in particular relates to an ochratoxin A nucleic acid aptamer and a preparation method thereof. Background technique [0002] Ochratoxin A (OTA) is a secondary metabolite produced by normal biological metabolism of Aspergillus and Penicillium. It is widely found in grains, wheat, barley and other grains. Studies have shown that the toxicity of OTA is not only manifested as Embryotoxicity, liver toxicity and nephrotoxicity, but also teratogenic, carcinogenic, mutagenic and immunosuppressive effects. Due to the strong carcinogenicity and pathogenicity of OTA, international agencies and countries around the world have made very strict regulations on the limit of ochratoxin in food. The maximum residues of OTA in grains and grain products in the European Union (EC) are 5 and 3μg / Kg, the maximum residue limit for OTA in wine and grape juice is 2μg / Kg; in the national standard GB 2761-2011, the limit ...

AI Technical Summary

Problems solved by technology

Both methods often require immobilization of the library or target, but the native conformation of the immobilized library or target may be affected to some extent

In addition, the carrier used for immobilization will also cause steric hindrance to the combination of the library and the target, which is not conducive to the screening of sequences with strong binding ability in the free state, so it is particularly important to develop non-immobilized nucleic acid aptamer screening methods

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