In this study,a simple enzyme-free co-system signal amplification method was proposed for the ultra-sensitive fluorescent detection of AFB1 in peanut samples.The sensing system cleverly combines Mg^(2+)dependent DNAzy...In this study,a simple enzyme-free co-system signal amplification method was proposed for the ultra-sensitive fluorescent detection of AFB1 in peanut samples.The sensing system cleverly combines Mg^(2+)dependent DNAzyme(MNAzyme)cleavage with co-system reactions.The prepared mixed solution was supplemented with AFB1 and signal molecules to facilitate specific binding of the target with the aptamer(Apt).Apt and competing chain cDNA complexes were dissociated,releasing cDNA which subsequently hybridized with complementary chain HDNA to activate the catalytic activity of MNAzyme.Subsequently,cleavage of fluorescent signal substrate F-DNA occurred,resulting in amplification of the fluorescent signal.Under optimal conditions,the fluorescent intensity is linearly correlated with the logarithm of the target AFB1 concentration in a dynamic range of 3 orders of magnitude from 0.1 ng mL^(-1) to 500 ng mL^(-1).The method has high selectivity for AFB1,and the detection limit is 0.083 ng mL^(-1).The recovery of the aptasensor was tested in peanut samples,and the recovery of the aptasensor was between 93.8 and 108%,which proved its practical application value in food safety field.展开更多
基金partly funded by the National Natural Science Foundation of China(32372423&32302190)the S&T Plan Project of Jiangsu Provincial(BE2022324).
文摘In this study,a simple enzyme-free co-system signal amplification method was proposed for the ultra-sensitive fluorescent detection of AFB1 in peanut samples.The sensing system cleverly combines Mg^(2+)dependent DNAzyme(MNAzyme)cleavage with co-system reactions.The prepared mixed solution was supplemented with AFB1 and signal molecules to facilitate specific binding of the target with the aptamer(Apt).Apt and competing chain cDNA complexes were dissociated,releasing cDNA which subsequently hybridized with complementary chain HDNA to activate the catalytic activity of MNAzyme.Subsequently,cleavage of fluorescent signal substrate F-DNA occurred,resulting in amplification of the fluorescent signal.Under optimal conditions,the fluorescent intensity is linearly correlated with the logarithm of the target AFB1 concentration in a dynamic range of 3 orders of magnitude from 0.1 ng mL^(-1) to 500 ng mL^(-1).The method has high selectivity for AFB1,and the detection limit is 0.083 ng mL^(-1).The recovery of the aptasensor was tested in peanut samples,and the recovery of the aptasensor was between 93.8 and 108%,which proved its practical application value in food safety field.
