The coordination effect of organic ligands in Ce-MOF brings about atomically dispersed Fe in CeO2 for TAC detection in commercial samples

Reducing the size of active species is a powerful means to improve the utilization rate of active metals and enhance the properties of bimetallic nanozymes. In this work, Fe was introduced into Ce-MOF through the coordination of Fe 3+ and organic ligands, and the coordination effect resulted in atomically dispersed Fe in the derived Fe/CeO 2 nanozyme. Due to the atomically dispersed Fe embedded in the lattice of CeO 2 , a large number of defect sites were generated, endowing the nanozyme with excellent peroxidase (POD)-like activity. The constructed total antioxidant capacity (TAC) sensor based on the POD-like activity of Fe 1.01 /CeO 2 nanozyme displayed a very wide linear concentration range for AA, Cys, Glu and Trolox. More importantly, this TAC sensor can be applied to the TAC detection in vitamin C tablets and beverages. This work provides theoretical guidance for the synthesis of high-performance bimetallic nanozymes for TAC detection.