Electromagnetically-driven microfluidic platform combining upconversion fluorescence sensing and photothermal sterilization for sensitive detection and in situ elimination of Vibrio parahaemolyticus in seafood

Traditional methods for detecting foodborne pathogens rely on culture techniques, while advanced analytical instruments, though more sophisticated, are unsuitable for rapid detection and cannot eliminate residual contamination from secondary sources. In this study, a novel method integrating near-infrared light-induced upconversion fluorescence sensing with photothermal sterilization was developed for the detection of Vibrio parahaemolyticus ( V. parahaemolyticus ). Upconversion nanoparticles (UCNPs) were used as a fluorescence signal carrier, and silica-modified hollow polydopamine (PDA)-loaded Fe 3 O 4 @Au (HS-PDA@Fe 3 O 4 @Au) functioned as a photothermal element. Based on fluorescence resonance energy transfer (FRET) and photothermal effect, an electromagnetic-driven microfluidic fluorescence platform was constructed to achieve sensitive detection and in situ sterilization of V. parahaemolyticus . More importantly, the platform allows programmable control of the shuttling of magnetic materials within the functional compartments of the sensing chip. Under optimal experimental conditions, the detection limit for V. parahaemolyticus was 5 CFU/mL, and the linear range was 8–10 6  CFU/mL. Additionally, the sterilization rate reached 100 % after 8 min of 980 nm near-infrared irradiation, effectively eliminating the residual pathogenic bacteria and preventing secondary pollution. Therefore, the platform developed in this study demonstrates great potential for on-site detection of V. parahaemolyticus in seafood.