Multifunctional magnetic composite nanomaterial for Colorimetric-SERS Dual-Mode detection and photothermal sterilization of Vibrio parahaemolyticus

In this study, a colorimetric and SERS dual-mode detection and photothermal sterilization method targeting Vibrio parahaemolyticus (V. parahaemolyticus) was proposed by preparing a multifunctional composite magnetic material (Fe3O4@MOF(Fe-Cu)-GNS-MBA-Apt) and integrating it with magnetophoretic chromatography technology. The composite magnetic material modified with aptamer demonstrated specific capture of V. parahaemolyticus in food matrices through magnetic separation. The dual-mode quantitative detection of V. parahaemolyticus was achieved by combining magnetophoretic chromatography for the separation of free materials and bacteria-material complexes and the peroxidase-like activity and SERS effect of the composite material. Under optimized conditions, the dual-mode sensor exhibited detection limits of 9 cfu·mL−1 (101 ––105 cfu·mL−1) in the colorimetric modality and 7 cfu·mL−1 (101 ––105 cfu·mL−1) in the SERS modality. Furthermore, the photothermal properties of the material allowed for the sterilization of bacteria in the detection solution within 4 min of near-infrared irradiation. Moreover, the developed method, based on the multifunctional materials, characterized by its rapid, sensitive, and efficient, was successfully applied to fresh shrimp samples, thus validating its potential for rapid pathogen diagnosis and contributing to the establishment of a safety control system of food and environmental detection process.