A highly sensitive point-of-care detection platform for Salmonella typhimurium by integrating magnetic enrichment and fluorescent CsPbBr@SiO.

A platform was designed based on FeO and CsPbBr@SiO for integrated magnetic enrichment-fluorescence detection of Salmonella typhimurium, which significantly simplifies the detection process and enhances the working efficiency. FeO served as a magnetic enrichment unit for the capture of S. typhimurium. CsPbBr@SiO was employed as a fluorescence-sensing unit for quantitative signal output, where SiO was introduced to strengthen the stability of CsPbBr, improve its biomodificability, and prevent lead leakage. More importantly, the SiO shell shows neglectable absorption or scattering towards fluorescence, making the CsPbBr@SiO exhibit a high quantum yield of 74.4%. After magnetic enrichment, the decreasing rate of the fluorescence emission intensity of the CsPbBr@SiO supernatant at 527 nm under excitation light at UV 365 nm showed a strong linear correlation with S. typhimurium concentration of 1 × 10~1 × 10 CFU∙mL, and the limit of detection (LOD) reached 12.72 CFU∙mL. This platform has demonstrated outstanding stability, reproducibility, and resistance to interference, which provides an alternative for convenient and quantitative detection of S. typhimurium.