An immune-scaffold relying biosensor for simultaneous detection of nitrofurazone and furazolidone

Here, to realize the simultaneous, simple, and highly sensitive detection for nitrofurazone and furazolidone, an immune-scaffold relying immunochromatographic assay was proposed. In this multi-detection immunochromatographic assay (MDICA), the immune-scaffold is composed of labeled anti-antibody IgG (Ab 2 ) and two anti-analyte monoclonal antibodies (Abs 1 ). A nanocomposite of MIL-101 (Cr)@AuNPs is used as the signal tag, where the unique optical property and biocompatibility of AuNPs and the protective effect of metal-organic framework can enable the nanocomposite possesses powerful signals, conjugating ability with antibodies and enhanced colloidal stability. In the immune-scaffold platform, the labeled Ab 2 is the core trestle, on the one hand to exempt Ab 1 from labeling requirement and offer strong detection signals, on the other hand to orient Abs 1 to expose their antigen-binding sites as well as improve the identification and binding efficiency between antigen and antibody. Compared with randomly fixed antibody in the conventional probe, a 6-fold reduction of applied Ab 1 amount can be achieved to produce the similar signal intensity in the immune-scaffold based method. In brief, the proposed MDICA system can effectively simplify the construction steps of MDICA, improve the Abs 1 utilization efficiency, heighten analytical performances, and providing an efficient, valuable reference for the establishment of other MDICAs.