Photothermal-driven magnetic ZnFe2O4 “three-in-one” nanoplatform for interfacial enrichment and rapid screening of 3-monochloropropane-1,2-diol in edible oils

Detection of 3-MCPD in lipid-rich food matrices remains challenging due to trace analyte levels, high viscosity, and severe matrix interference. Herein, a photothermal-driven magnetic “three-in-one” sensing platform based on L -cysteine-functionalized ZnFe 2 O 4 ( L -ZFO) nanoparticles was developed for rapid and sensitive screening of 3-MCPD in edible oils. The multifunctional platform integrates magnetic enrichment, photothermal-assisted signal amplification, and colorimetric sensing, enabling efficient extraction and detection with minimal sample pretreatment. Benefiting from the synergistic interfacial enrichment and photothermal enhancement, the proposed method exhibited a linear range of 0.01–0.20 mg/L with a low detection limit of 1.4 μg/L. The platform showed acceptable recoveries of 75.0–92.0% and relative standard deviations below 5.8% in edible oil samples. Moreover, comparable responses obtained in buffer and oil matrices demonstrated excellent anti-interference capability toward complex lipid systems. The recyclable L -ZFO probe also exhibited good stability and reproducibility over 3 cycles. This work provides an elimination of pretreatment strategy for rapid on-site screening of 3-MCPD in edible oils.