Fluorescent Aptsensor For The Detection Of Ochratoxin A

Ochratoxin(OT)is a group of structurally similar secondary metabolites produced by fungi of the genus Penicillium and Aspergillus,and is a very stable natural toxin.Among the discovered ochratoxins,there are four compounds A,B,C,and D.The most common and most toxic is ochratoxin A(OTA).Because of its lipophilicity,it is stored in the liver and The kidney is not easily degraded and destroys the immune function of the human body,so it is a highly carcinogenic and mutagenic pollutant,which is now classified as a category 2B carcinogen by IARC.The health of the population depends to a large extent on the safety of food production.According to the report of the Food and Agriculture Organization of the United Nations,25%of the world’s crops are contaminated by OTA.It is widely found in cereals,peanuts,juice,Food-borne products such as beer,wine,coffee,cocoa and animal feed seriously threaten human and animal health.Therefore,it is of great significance to develop high-accuracy,sensitive,convenient and low-cost detection methods.At present,there are many methods for detecting OTA,mainly instrumental analysis and immunoassay.However,these methods are very time-consuming and generally take about two days to produce results.They have complicated operation procedures,and the sample preparation and preparation of the solution used are very complicated,and the amount of solvent used is expensive.Therefore,it is particularly important to find a simple and fast method to detect OTA.In this paper,two label-free fluorescent aptamer biosensors are established to achieve trace detection of OTA:1.Based on Exonuclease Ⅰ(Exo Ⅰ)activity and 4,4’-(1E,1’E)-2,2 ’-(anthracene-9,10-diyl)bis(ethylene-2,1-diyl)bis(N,N-dimethylaniline)(DSAI)fluorescent dye and aptamers will cause aggregation induction With the characteristics of luminescence,a label-free fluorescent aptamer biosensing platform was constructed to achieve trace detection of OTA.The detection method has good sensitivity and selectivity,its linear range is:5～500 ng/mL,and the detection limit is:1.9 ng/mL.2.Using SWCNHs as a quencher to quench the SYBR Gold fluorescent dye that binds to the aptamer and a label-free aptamer biosensing platform based on the specific binding of the OTA to the target OTA to quantify OTA Detection.The detection platform shows good sensitivity,its linear range is:5～500 ng/mL,and the detection limit is 2.3 ng/mL.In order to verify that the above two detection systems are not disturbed by the sample matrix,we evaluate their effectiveness and practicability through actual samples.