Study On The Visual Detection Methods For Zearalenone

Zearalenone is a non-steroidal estrogen-like mycotoxin produced by Fusarium,which mainly contaminates cereals and feedstuffs.Zearalenone has strong reproductive toxicity,neurotoxicity,hepato-renal toxicity and carcinogenicity,which cause great harm to humans and animals.At present,although the methods for detecting zearalenone can complete the detection of zearalenone in foods,but they need complicated pretreatment,expensive instruments and professional operation.It is not suitable for rapid detection of large quantities of samples.The visual detection method is simple in operation,short in detection time and can be judged visually by naked eyes.The visual detection can satisfy the high sensitivity,high specificity and rapid detection requirements of zearalenone.The main research work is as follows:1.The visual detection method for zearalenone has been established based on competitive emzyme-linked aptamer:A biotinylated aptamer of zearalenone was immobilized on the surface of the wells of a microplate by biotin-avidin binding.The aptamer’s complementary strands（cDNA）was ligated with horseradish peroxidase（HRP）to form a cDNA-HRP signal probe.The cDNA-HRP signal probe and target competed for binding to the aptamer.The visual detection of zearalenone can be achieved after adding TMB reagent and stop solution.Under optimized conditions,the correlation between concentration of zearalenone and A₄₅₀50 absorbance was observed to be linear within the range of 1 ng/mL¹0000 ng/mL（R²=0.9913）,and the limit of detection was 0.7 ng/ml.The developed method has good consistensy with the result of ELISA method,which proved that this experimental method can be used for the real sample detection.2.The visual detection method for zearalenone has been established based on aptamer-modified gold nanoparticles:The thiolated aptamer of zearalenone and the thiolated complementary strand（cDNA）of aptamer connected to the surface of AuNPs to form capture probes and signal probes,respectively.In the presence of zearalenone,the aptamer bound to the target.AuNPs aggregated at high salt concentration and the color change from red to purple.In the absence of zearalenone,aptamer and cDNA hybridization formed a stable network between nanoparticles.AuNPs did not aggregate at high salt concentrations and the color was still red.Under the optimal conditions,there was a linear relationship between the concentration of zearalenone and A₆₅₀/A₅₂₅25 ranging from 0.1 to 1000 ng/ml（R²=0.9952）,and the limit of detection is 0.1 ng/ml.The developed method has good consistensy with the result of ELISA method,which proved that this experimental method can be used for the real sample detection.3.The visual detection method for zearalenone has been established based on Au-MoS₂enzyme mimetics for signal anplification:A biotinylated aptamer was immobilized on the surface of the wells of a microplate by biotin-avidin binding.The zearalenone aptamer’s cDNA was ligated with Au-MoS₂ enzyme mimetics to form a cDNA-Au-MoS₂ signal probe.Au-MoS₂ enzyme mimetics has the function of signal amplification.The cDNA-Au-MoS₂signal probe and target competed for binding to the aptamer.The visual detection of zearalenone can be achieved after adding TMB reagent and stop solution.Under optimized conditions,the correlation between concentration of zearalenone and A₄₅₀50 absorbance was observed to be linear within the range of 0.1 ng/mL¹0000 ng/mL（R²=0.9953）,and the limit of detection is 0.05 ng/ml.The developed method has good consistensy with the result of ELISA method,which proved that this experimental method can be used for the real sample detection.