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 (H 2 O 2 ) is widely used as disinfectant and bleaching agent in food industry, but excessive amounts of H 2 O 2 residue in foods can cause serious adverse effects on human health. Herein, a fluorescent sensing strategy for rapid detection of H 2 O 2 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 H 2 O 2 further quenches the fluorescence remarkably, which is attributed to the H 2 O 2 -promoted electron transfer. Based on H 2 O 2 concentration-dependent fluorescence quenching of CDs/nanoceria, the fluorescence method for H 2 O 2 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 H 2 O 2 , offering a promising method for rapid sensing of H 2 O 2 on site. The fluorescent strategy is applied to H 2 O 2 residue detection in milk, dried bean curd, and chicken feet samples successfully, suggesting its great potential for applications in food and agricultural fields.