Antibody-biotin-streptavidin-horseradish peroxidase (HRP) sensor for rapid and ultra-sensitive detection of fumonisins.

Fumonisins (FBs) exist widely in crops, foods and feeds. Consumption of FBs contaminated corn can cause oesophageal cancer. So it is necessary to develop sensitivity methods for its detection. Here, we report an enhanced assay for rapid and ultra-sensitive detection of FBs based on nanomagnetic beads (NMBs) and antibody-biotin-streptavidin-HRP. Because antibody-BNHS can bind with several number of streptavidin-HRP, the signal amplification of the catalytical oxidation of TMB was enhanced. The detection limit of sensor was down to 0.21 ng mL^-1 with a linear range from 0.31 to 162.42 ng mL^-1. Since NMBs provide a nearly "in solution" reaction, they lead to a shortened reaction time (22 min) than that of flat solid-phase based traditional assay. Furthermore, the recoveries obtained by standard FBs spiked to maize samples were from 100.6 to 107.3%. This enhanced assay supplied a rapid, sensitive and reliable method for detection of FBs in maize.