Detecting harmful pathogens in food is not only a crucial aspect of food quality management but also an effective way to ensure public health. In this paper, a complete nuclear magnetic resonance biosensor based on a novel gadolinium (Gd)-targeting molecular probe was developed for the detection of Salmonella in milk. First, streptavidin was conjugated to the activated macromolecular polyaspartic acid (PASP) via an amide reaction to generate SA–PASP. Subsequently, the strong chelating and adsorption properties of PASP toward the lanthanide metal gadolinium ions were exploited to generate the magnetic complex (SA–PASP–Gd). Finally, the magnetic complex was linked to biotinylated antibodies to obtain the bioprobe and achieve the capture of Salmonella. Under optimal experimental conditions, the sensor we have constructed can achieve a rapid detection of Salmonella within 1.5 h, with a detection limit of 7.1 × 103 cfu mL–1.
Rapid screening and early warning of pathogenic bacteria in food is the key to prevent and control the spread of foodborne diseases . Biotin–streptavidin system and membrane filtration technology were combined to develop a novel nuclear magnetic resonance (NMR) immunosensor based on biomacromolecule O-carboxymethyl chitosan (O-CMCS) target gadolinium (Gd) probe for rapid detection of Salmonella anatum in milk. Under optimal experimental parameters, the proposed NMR immunosensor could detect Salmonella in milk with a limit of detection of 1.8 × 10 4 cfu mL −1 within 2 h. Furthermore, the immunosensor exhibited good specificity, sensitivity and reproducibility, which could achieve the direct determination of biological samples with complex composition. Hence, the developed assay might have great application potential for the rapid detection of Salmonella in food.
危险品化学品经营许可证（带存储）