Ultrasensitive SERS biosensor for synchronous detection of Escherichia coli O157:H7 and Pseudomonas aeruginosa via Cecropin 1-functionalized magnetic tags-based lateral flow assay

Healthcare-associated infections (HAIs) have increasingly become a threat to global health. Rapid, accurate, and reliable detection of HAI-related bacteria is urgently needed. Here, we presented a novel antimicrobial peptide-based surface-enhanced Raman scattering lateral flow assay (SERS-LFA) for the detection of multiple HAI-related bacteria. Antimicrobial peptide cecropin 1(CP1) was immobilized on the surface of Fe3O4@Au by the streptavidin-biotin system to capture Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli O157:H7 (E. coli O157:H7) simultaneously. The synthesized Fe3O4@Au-CP1 exhibits excellent broad-spectrum capturing ability, rapid magnetic enrichment function, and superior antibacterial activity. LFA strips enable the specific detection of two target bacteria in a quick and simple manner, with bacterial type differentiation via corresponding monoclonal antibodies sprayed. The highly sensitive SERS signals and the amplification effect of streptavidin-biotin significantly improved the sensitivity of detection. The LODs of P. aeruginosa and E. coli O157:H7 were 12 and 16 cells/mL, respectively. This assay also exhibited good specificity and reproducibility when applied to urine samples. Therefore, Fe3O4@Au-CP1-based SERS-LFA has great potential for detecting multiple bacteria after infection as well as regularly monitoring therapeutic efficacy.