Dual-Mode Ratiometric Fluorescence Ce-UiO-66-NH₂ Sensor for Hydrogen Peroxide Detection

Hydrogen peroxide (H2O2) is extensively used in the food industry for its effective sterilization and bleaching properties. Excessive intake of H2O2 can lead to poisoning, respiratory difficulties, and even cancer. Therefore, it is crucial to establish a method for the detection of H2O2. In this study, a dual-mode ratiometric fluorescence nanozyme sensor was developed and a smart label for the RGB analysis was constructed, which can accurately detect H2O2. The sensor exhibited pronounced color changes from colorless to yellow, accompanied by a fluorescence shift from blue to yellow. Additionally, ultraviolet–visible (UV–vis) absorption demonstrated a linear correlation with H2O2 concentration ranging from 10 to 120 μM, with high sensitivity (Limit of detection, LOD = 1.06 nM). Fluorescence intensity ratio also exhibited a linear correlation ranging from 10 to 500 μM, with high selectivity and sensitivity (LOD = 0.33 μM). Based on this, the sensor had been successfully applied to the detection of the H2O2 concentration in leafy greens. Furthermore, we integrated the sensor with cellulose-based filter paper, which allowed for the quantitative detection of H2O2 through the RGB analysis. These results demonstrated the excellent performance of the sensor in detecting H2O2, which provided robust technical support for ensuring food safety.