AuPt/MOF–Graphene: A Synergistic Catalyst with Surprisingly High Peroxidase-Like Activity and Its Application for H2O2 Detection

Here, we report ZIF-8-reduced graphene oxide (ZIF-8–rGO)-supported bimetallic AuPt nanoparticles (AuPtNPs) as a novel peroxidase mimic for high-sensitivity detection of H2O2 in neutral solution. ZIF-8–graphene oxide (ZIF-8–GO) is first synthesized via a simple wet-chemistry process and subsequently immobilized with AuPtNPs via a reduction method. The resultant AuPt/ZIF-8–rGO shows enhanced peroxidase-like catalytic activity and it is applied for the electrochemical detection of H2O2 in a wide concentration range, from 100 nM to 18 mM, with a very low detection limit of 19 nM (S/N = 3). This good electroanalytical performance of AuPt/ZIF-8–rGO is owing to the ultrasmall size and high dispersion of the AuPtNPs, the strong metal–support interaction between the AuPtNPs and ZIF-8–rGO bisupport, and the sandwich-like structure comprising porous ZIF-8 and loosely packed rGO nanosheets. The AuPt/ZIF-8–rGO is employed for the practical detection of H2O2 in human serum samples with desirable properties. Therefore, the novel AuPt/ZIF-8–rGO is a promising nanozyme for various biotechnological and environmental applications.