Nitrogen-doped coral-like Fe-MOFs prepared with dielectric barrier discharge (DBD) plasma for H2O2 detection

Hydrogen peroxide (H2O2) was closely related to environmental pollution and cell damage. It's of great significance to use a simple colorimetric method to achieve efficient and rapid detection of H2O2. Fe-HEDP (prepared with etidronic acid monohydrate) and Fe-[(HEDP)(2MI)]x (prepared with etidronic acid monohydrate and 2-methimidazole) were synthesized by DBD plasma method, and applied as artificial peroxidase in the detection of hydrogen peroxide (H2O2). The different molar ratios of metals and organic ligands, as well as the introduction of N element, had great influence on the detection performance of H2O2. Fe-[(HEDP)(2MI)]2 synthesized with the molar ratios of metal and organic ligands of 2:1 exhibited excellent performance. Fe-[(HEDP)(2MI)]2 exhibited a coral-like morphology shape composed of nanorods with abundant angular defects, which could provide more active sites. Fe-[(HEDP)(2MI)]2 also exhibited higher content of graphite-N and surface oxygen, which could anchor more Fe, thereby promoting the Fenton reaction. Fe-[(HEDP)(2MI)]2 showed an excellent linear relationship (R2=0.998) in the H2O2 concentration range of 0–500 μM with an LOD of 80 μM. Radical trapping experiments were carried out, proving that ·OH was the main active species, and the detection mechanism was proposed. Therefore, Fe-[(HEDP)(2MI)]2 provided a new material for realizing efficient and rapid detection of H2O2.