A gold nanoflower particle-based immunochromatographic assay sensor for on-site detection of six species of Salmonella in water and food samples

Background: Salmonella is a prevalent zoonotic pathogen that threatens food safety and human health. Owing to the large number of Salmonella species and their significant variations in pathogenicity and virulence, it is difficult to classify Salmonella strains quickly, which makes rapid detection of Salmonella outbreaks and research on foodborne diseases difficult. Results: Therefore, in this study, an ICA sensor for the detection of multiple Salmonella strains with high pathogenicity based on broad-spectrum Salmonella antibodies was developed using AuNFs as probes. Compared with other Salmonella ICA sensors, the sensor was able to detect six different types of Salmonella. The ICA sensor had a visual LOD of 104 CFU/mL for S. Paratyphi A, S. Typhimurium, S. Paratyphi B, S. Saintpaul, S. Heidelberg and S. enterica. The ICA sensor had no cross-reaction with 20 common foodborne pathogens, which could effectively avoid incorrect results caused by cross-reaction and delay accurate tracing of pathogenic bacteria. Moreover, the feasibility of the ICA sensor was verified by detecting Salmonella in spiked drinking water, orange juice, and milk. The ICA sensor achieved a visual detection limit of 104 CFU/mL and detected as low as 1 CFU/mL in chicken and egg samples after 6-8 h of enrichment. Significance: In conclusion, this sensor offers a rapid, cost-effective, and reliable solution for the on-site detection of multiple Salmonella strains, addressing critical needs in food safety and public health.