Integration of three non-interfering SERS probes combined with ConA-functionalized magnetic nanoparticles for extraction and detection of multiple foodborne pathogens

A sandwich-structured SERS biosensor has been constructed for simultaneous detection of multiple pathogenic bacteria, consisting of non-interfering SERS probes for bacterial labeling and ConA-functionalizd magnetic nanoparticles for bacteria extraction. A the preparation method of PP3 SERS probe with high Raman activity is reported for the first time. Since the PP3 SERS probe has a very strong Raman peak at 2081 cm −1 in the “Raman silent region,” the mixed SERS probe formed with MP1 and DP2 can meet the needs of multiple foodborne pathogen detection. Significantly, S. aureus , E. coli , and P. aeruginosa can be successfully extracted upon external magnetic field, and the limit of detection (LOD) is 1 CFU‧mL −1 , lower than that of the congeneric detectors. This work paves a new way for the construction of a novel detector and absorbent for different bacteria in complex samples by using SERS probe. Graphical Abstract