Ultrasensitive strips for the quadruple detection of nitrofuran metabolite residues.

In this biosensor system, metabolite residues were derived by using a previous B-CBA synthesis method to label a biotin moiety for enrichment by streptavidin coated magnetic beads. Antibodies specific for derivatives were conjugated with carboxyl-modified barcode DNAs which were used as templates for strand displacement amplification (SDA). The assay can detect trace levels of 7.20 ppt of SEM, 11.58 ppt of AHD, 7.24 ppt of AOZ and 2.31 ppt of AMOZ, respectively.