Monoclonal antibody-based fluorescence polarisation immunoassay for nifursol in feed

Abstract

Novel tracers were designed and then used to develop a rapid, specific and sensitive fluorescence polarisation immunoassay (FPIA) method to detect nifursol in feed. The 3-((2-(2-hydroxy-3,5-dinitrobenzoyl)hydrazono)methyl)benzoic acid was used for the production of immunogen and 3,5-dinitrosalicylic acid was used for synthesis of fluorescein-labelled tracer. Based on monoclonal antibody and tracer, an optimised FPIA method was established with IC 50 of 5.0 ng mL (1 , and low cross-reactivity with other nitrofurans ( B0.05%). FPIA provides a suitable means for screening of a large number of samples. The limits of detection calculated from the analysis of 20 known negative feed samples (pig feed, chicken feed and fish feed) were 0.4Á0.8 ng g (1 (mean'3 SD). Recoveries of nifursol fortified ranged from 85.0 to 95.0%. The coefficients of variation were less than 10%.

A camelid VHH-based fluorescence polarization immunoassay for the detection of tetrabromobisphenol A in water

“…Tracer bands were scraped from the TLC plates and assessed for relative binding capacity with the VHH according to the previous report. 31 The mP value of borate buffer is around zero and the intensity of blank buffer is about 2000. When the tracer was diluted by 10 000 times, at a concentration of 1.0 nM, the intensity was around 5-fold the signal of the borate buffer, and it was used as the optimal dilution for the tracer, as in the previously reported method.…”