Preparation and detection methods of fluorescence sensor for aflatoxin toxin production gene nor-1

Abstract

The invention discloses a preparation method and detection method of a fluorescence sensor for an aflatoxin toxin production gene nor-1. The fluorescence sensor is a long-arm hairpin probe based on specific recognition of the aflatoxin toxin production gene nor-1; and the two ends of the long-arm hairpin probe are provided with NH2 and SH correspondingly, a CdTe/CdS quantum dot of an upper core-shell structure is modified by the NH2, and upper gold nanoparticles (AuNPs) are modified by the SH. The preparation method comprises the steps: a CdTe/CdS quantum dot solution is prepared for standby application; the AuNPs are prepared for standby application; and the long-arm hairpin probe is modified. Detection comprises construction of the fluorescence sensor, when the target nor-1 appears, thenor-1 and the hairpin probe are subjected to specific complementary pairing, the hairpin probe is straightened, the distance between the CdTe/CdS quantum dot and the AuNPs is enlarged, transferring offluorescent resonance energy is blocked, thus fluorescence of the CdTe/CdS quantum dot is recovered, the concentration of the nor-1 is tested through the fluorescence recovery intensity, and thus thenor-1 is quickly detected. The prepared fluorescence sensor has the advantages that flexibility, simpleness, quickness and the like are achieved, the toxin production gene is detected from the source, the cost is low, and detection is quick.

Description

technical field [0001] The present invention relates to the field of fluorescence sensing, in particular to a fluorescent sensor for source detection of aflatoxin-producing gene nor-1 constructed by utilizing the signal quenching of fluorescence resonance energy transfer and the fluorescence recovery mechanism of target specific recognition. Preparation and rapid detection method for nor-1. Background technique [0002] Aflatoxin was identified as a carcinogen as early as 1961, especially the toxicity of aflatoxin B1 is 68 times that of arsenic and 10 times that of potassium cyanide. It is the most toxic and carcinogenic substance found so far. Natural pollutants, and according to the report of the World Food and Agriculture Organization, about 25% of the world's grains produce aflatoxins due to mildew every year, and aflatoxin pollution in grains has become a global problem. If aflatoxin-producing bacteria can be detected from the source and effective monitoring can be car...

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Problems solved by technology

[0004] Semiconductor nanomaterial quantum dots have the characteristics of adjustable emission wavelength and relatively stable fluorescence performance. They have been used as signal markers for fluorescent bioprobes. However, when a single quantum dot is directly used as a marker, it is difficult to disperse and easy to agglomerate. , Fluorescence intensity is susceptible to defects such as particle size and dispersion state, and the preparation of core-shell quantum dots can effectively improve these defects, which is an effective method for fluorescent biosensors

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