Dendritically hybrid-DNA double fluorescence amplification technology ultra-sensitive detection of AFM1 in food.

Aflatoxins are highly carcinogenic and mutagenic. Among them, aflatoxin M1 (AFM1) is a hydroxylated metabolite that seriously poses threats to human health and safety, so there is a need to construct an efficient and sensitive detection system for AFM1. In this study, an analytical method was established for ultra-sensitive determination of AFM1 in food based on dendritic hybridization chain reaction (HCR) dual-amplification. The prepared carboxylated silica was modified with AFM1 antibody, dendritic (S) chain and initiator (H0) chain as fluorescent probes, the whole AFM1 antigen was coated on the microplate, and the antibody on the fluorescent probes competed with the AFM1 standard for binding to the whole antigen. Then the fluorescence response value of the supernatant was measured, which displayed a good linear relationship with the standard concentration. The detection range was 10 pg/mL to 10 μg/mL, and the limit of detection was 5.41 fg/mL, which was in line with the limit value of China's national standard. In addition, the spiked recovery rate was between 84.77 % and 115.70 %. The method developed in this study displays an increase of three orders of magnitude in comparison with indirect competitive enzyme-linked immunosorbent assay (ic-ELISA), in the detection of AFM1, showing ultra-high sensitivity, which satisfies the needs of AFM1 analysis and detection in food. This biosensing method also has reference value for the detection of other toxins in food. • A signal amplification technique based on dendritic hybrid DNA was developed. • An efficient and ultra-sensitive method for AFM1 detection was developed. • The LOD of this method is three orders of magnitude lower than that of ic-ELISA. • The biosensing method has reference value for the detection of other toxins. [ABSTRACT FROM AUTHOR]