Perovskite Nanomaterial-Engineered Multiplex-Mode Fluorescence Sensing of Edible Oil Quality

Water-soluble fluorescence nanomaterials are widely applied for water-phase food safety monitoring. However, there is still a challenge for the development of oil-soluble fluorescence nanomaterials for oil-phase food safety detection. Particularly, the edible oil quality has a huge impact on human health, in which excessive acid number (AN), 3-chloro-1,2-propanediol (3-MCPD), and moisture content (MC) are critical monitoring factors. Herein, orange-emitting oil-soluble CsPbBr1.5I1.5 quantum dots (QDs) were prepared and applied for AN and 3-MCPD detection depending on fluorescence quenching and wavelength shifts. A "turn-off" fluorescence sensor and "wavelength-shift" fluorescence colorimetric sensor were fabricated for AN and 3-MCPD detection. Water-sensitive mesoporous silica-coated CsPbBr1.5I1.5 QDs were employed for the establishment of ratiometric fluorescence sensors for MC monitoring by introducing water-stable green-emitting CsPbBr3 nanosheets (NSs) as reference probes. Perovskite nanomaterial-engineered multiplex-mode fluorescence sensors were proposed for the detection of AN, 3-MCPD, and MC in edible oil, with the limits of detection (LODs) of 0.71 mg KOH/g, 39.8 μg/mL 3-MCPD, and 0.45% MC, respectively. This work not only expands the application of perovskite nanomaterials in the bioanalysis field but also provides new materials and novel approaches for the multiplex-mode oil-phase food safety monitoring.