A dextran mediated multicolor immunochromatographic rapid test strip for visual and instrumental simultaneous detection of Vibrio cholera O1 (Ogawa) and Clostridium botulinum toxin A

The authors describe a multicolor immunochromatographic test strip format for simultaneous detection of Vibrio cholera O1 (Ogawa) and of the Clostridium botulinum toxin type A. Respective monoclonal antibodies were conjugated to CdTe quantum dots (QDs) with green and orange emission color. Activated dextran is used as a cross-linker. The CD labeled antibodies were then covered with denatured reduced BSA (dBSA-QD). Under illumination, the test gives lines with emission peaks at 540 nm and 570 nm, respectively. This lateral flow assay system can detect V. cholerae down to 1000 cfu·mL −1 levels, and C. botulinum toxin down to 0.8 ng·mL −1 . The method allows assays to performed within 10 min without any sample pretreatment. Graphical Abstract Dextran mediated multicolor immunochromatographic test strip for simultaneous detection of V. cholera O1 and C. botulinum toxin type A.