Bacterial surface informatics reliant on multi-mechanism simultaneous detection for Salmonella typhimurium and...

Fully excavating and utilizing the rich information presented on bacterial surfaces can open innovative solutions for the multi-mechanism detection of food-borne pathogens. In this work, a colorimetric-fluorescence dual-signal lateral flow immunoassay was used to establish a simultaneous detection strategy integrating five physical, chemical, and biometric combining mechanisms for Salmonella typhimurium (S. typhimurium) and Staphylococcus aureus (S. aureus). To improve sensitivity, a layer-by-layer design of aggregation-induced emission nanosphere@ polydopamine@ platinum (AIENS@PDA@Pt) nanostructure with excellent colorimetric-fluorescence signal, abundant recognition sites, and rough surface was employed as a signal tag. Under optimal conditions, the colorimetric detection limit of the multi-mechanism reliant simultaneous detection LFIA (multi-MRSD LFIA) for S. typhimurium and S. aureus is 2 × 10⁴ and 5 × 10⁴ cfu·mL^-1, respectively, and the fluorescence detection limit is 500 cfu·mL^-1 for both target bacteria. This study introduces a novel approach for multi-target, multi-mechanism, and multi-signal output detection of bacteria, providing a significant direction for pathogen research.