Rapid detection of Salmonella in milk with a nuclear magnetic resonance biosensor based on a streptavidin–biotin system and a polyamidoamine-dendrimer-targeted gadolinium probe

Rapid and sensitive detection technology is the key to preventing food-borne disease outbreaks. In this study, a low-field nuclear magnetic resonance (NMR) biosensor based on polyamidoamine dendrimers was prepared for rapid of Salmonella in milk. The dendrimer biotinylated by amide reaction chelated diethylene triamine pentacetate acid gadolinium form complexes. antibody complexes were combined through streptavidin–biotin system using streptavidin as an intermediate bridge obtain immunoprobe. captured immunoprobe via antigen–antibody interaction then separated from mixture membrane filtration. Finally, longitudinal relaxation signal filtrate obtained NMR. had excellent anti-interference capability could detect within 1.5 h at sensitivity 103 cfu mL–1. This method NMR can realize complex samples has potential be quick nondestructive detecting target bacteria.