A fluorescent biosensor for detection of zearalenone

A fluorescent biosensor was developed on a KinExA(TM) now spectrofluorimete r for the near real-time detection of soluble zearalenone. Briefly, solutio ns of zearalenone and a monoclonal antibody directed against a protein conj ugate of zearalenone, were incubated for thirty minutes to permit equilibri um binding to occur. The reaction mixture was then passed over a packed col umn of small beads (98 mu m) whose surfaces were coated with a covalent con jugate of zearalenone and bovine serum albumin(BSA). Following a short wash with buffer to remove excess unbound primary reagents, the packed beads we re subjected to a brief contact with fluorescein isothiocyanate-labeled pol yclonal secondary antibody directed against the primary monoclonal, once ag ain followed by a short wash As this assay depends on the ability of solubl e antigen to compete with immobilized antigen, increasing concentrations of zearalenone result in decreasing fluorescence observed on the bead pack. T his assay is rapid (congruent to 60 minutes) and can be adapted to various other analytes of interest.