A facile fluorescent sensing strategy for determination of hydrogen peroxide in foods using a nanohybrid of nanoceria and carbon dots based on the target-promoted electron transfer

Hydrogen peroxide (H2O2) is widely used as disinfectant and bleaching agent in food industry, but excessive amounts of H2O2 residue in foods can cause serious adverse effects on human health. Herein, a fluorescent sensing strategy for rapid detection of H2O2 in foods is described based on a nanohybrid system of nanoceria and carbon dots (CDs). Nanoceria can reduce the fluorescence intensity of CDs, but the presence of H2O2 further quenches the fluorescence remarkably, which is attributed to the H2O2-promoted electron transfer. Based on H2O2 concentration-dependent fluorescence quenching of CDs/nanoceria, the fluorescence method for H2O2 determination is established with a linear range of 0.1–100 μM and a detection limit of 0.047 μM. Meanwhile, the smartphone is utilized as a portable platform for facile and low-cost detection of H2O2, offering a promising method for rapid sensing of H2O2 on site. The fluorescent strategy is applied to H2O2 residue detection in milk, dried bean curd, and chicken feet samples successfully, suggesting its great potential for applications in food and agricultural fields.