Cyclic peptide: a safe and effective alternative to synthetic aflatoxin B-1-competitive antigens

摘要

Aflatoxin B-1 (AFB(1)) is one of the major mycotoxins, which naturally occurs in food and agricultural products. In this study, a cyclic peptide (CVPSKPGLC) mimicking AFB(1) was used to develop a biotinylated peptide-based immunoassay (bp-ELISA) for AFB(1) determination. This cyclic peptide was isolated from a commercially available phage-displayed random 7-mer cyclic peptide library, and then synthesized chemically. Instead of phage particles, the peptide was biotinylated and used to detect AFB(1) by bp-ELISA, with an IC50 of 0.92ng/mL, which was approximately 60-fold better than that of phage ELISA. Good recoveries (83-102) were obtained in spiked rice and corn samples, which were further validated by high-performance liquid chromatography-fluorescence detector. As better sensitivities (0.92-1.21ng/mL) were obtained by bp-ELISA even using selected anti-AFB(1) antibodies prepared previously in laboratory, this cyclic peptide is suitable as a substitute for synthetic competitive AFB(1) antigens in food contamination monitoring.