Smart phone based immunosensor coupled with nanoflower signal amplification for rapid detection of Salmonella Enteritidis in milk, cheese and water

摘要

Salmonellais a standout amongst the most foodborne pathogens causing harmful disease. To protect consumers from food poisoning due toSalmonellainfection, it is important to develop a quick, simple, reliable and sensitive method, which can detectSalmonellain foods at low concentration in a timely manner. We have effectively established a novel magnetic nano biosensor with high sensitivity for the visual and quantitative detection ofS.Enteritidis from milk, cheese and water. Milk, cheese and water samples inoculated with different concentrations ofS. Enteritidis have been tested using antiS.Enteritidis streptavidin magnetic beads and biotin labeled antibody as capture platform and coupled with nanocomposite (detecting antibody-HRP enzyme and inorganic nanoflower), where the signal amplification based on HRP enzyme which is enhanced by the action of nanoflower and produce visual color easily detected by the smartphone device at a very low concentration. The developed assay was able to detectS.Enteritidis in tap water, milk and cheese, with a detection limit of 1.0 CFU mL−1and 1.0 CFU/g, respectively. Recoveries percentages of spiked milk, cheese and tap water samples with102, 103and 104 CFU mL−1from liveSalmonellawere 98.2, 96.1 and 95.4 (in milk), 94.3, 98.6 and 99.5 (in cheese) and 95.8, 101.2 and 97.8 (in water) using designed device, respectively. The effective application of this innovation in milk and cheese indicates the possibility of its application in various food products.