y Conjugation of Different Aflatoxin Derivatives to Proteins and Their Use as Heterologous Antigens in Immunoassay Development

Analysis of small molecule contaminants using biochemical methods like ELISA or biosensors often require their conjugation to a bigger molecule. Protein conjugates of aflatoxins (AFs), potent carcinogenic mycotoxins, are widely used in antibody and analytical assay development. There are more than 20 naturally occurring AF derivatives four of which are regulated by international authorities. AFB1, the most abundant AF derivative, is also the most commonly utilized one in protein conjugation reactions. In this study, we demonstrated that the use of different AF derivatives can is an aid for modifying the conjugation efficacy to obtain optimal hapten densities. With a Mannich-type reaction scheme, AFG1 and AFG2 conjugates showed more than 3-fold higher hapten densities compared with AFB1 and AFB2 conjugates. We also showed that the use of heterologous antigens in AF immunoassay development decreases the production costs without affecting assay sensitivity.