Colorimetric Test Paper for H2O2 Determination Based on Peroxidase‐Like Activity of an AuFe/ZIF‐8‐Graphene Composite

Herein, we prepared a bisuppport‐based bimetallic nanoparticle composite AuFe/ZIF‐8‐graphene. It exhibited high peroxidase activity compared to those hybrids without graphene support, which demonstrated the regulatory effect of graphene on the catalytic activity. SEM, TEM, EDX, XRD, FT‐IR and XPS characterization showed that Au and Fe3O4 NPs were successfully immobilized on ZIF‐8‐rGO carriers. Kinetic analysis confirmed that the fabricated composites showed better Km and Vmax for H2O2 than HRP and some other reported peroxidase mimics. Under the optimal conditions, a sensing assay for H2O2 determination was constructed with a linear detection range of 0.01–2.5 mM and a detection limit of 0.63 μM. On this basis, a colorimetric test paper with its standard card was prepared for rapid visualization detection. It realized H2O2 detection in the range of 0.01‐500 mM and was further successfully applicated in the semi‐quantitative detection of H2O2 in actual spiked water samples. This achievement was expected to encourage the development of rapid visual detection for other pollutants in environmental and medical field. AuFe/ZIF‐8‐rGO hybrids were synthesized using a wet chemical method. Kinetic analysis confirmed that the fabricated composites showed better Km and Vmax for H2O2 than HRP and some other reported peroxidase mimics. Based on this, a colorimetric test paper with its standard card was prepared for rapid visualization detection.