Synthesis of Amorphous/Crystalline Hetero‐Phase Nanozymes With Peroxidase‐Like Activity by Coordination‐Driven Self‐Assembly for Biosensors

Nanozymes and amorphous nanomaterials attract great attention owing to their extraordinary properties. However, the requirements for special synthesis conditions become the bottleneck of their development. Herein, a new strategy involving the DNA-based coordination-driven self-assembly is reported for the synthesis of a novel amorphous/crystalline hetero-phase nanozyme (Fe-DNA). For the synthesis of both nanozymes and amorphous materials, this strategy is simple and controllable, avoiding the traditionally employed harsh conditions. Benefitting from the amorphous structure and the superior physicochemical properties, the synthesized Fe-DNA nanozyme is subsequently found to exhibit a smaller Michaelis constant value for hydrogen peroxide (H₂ O₂ ) (0.81 mm) than that of horseradish peroxidase (HRP) (3.70 mm), demonstrating the stronger affinity of the Fe-DNA nanozyme toward H₂ O₂ . The Fe-DNA nanozyme also shows significant peroxidase-like activity but only negligible oxidase-like activity, a characteristic which releases the corresponding assay system from oxygen interference, thereby improving the performance of the nanozyme-based sensing platform. In addition, compared with other nanozymes, the novel Fe-DNA nanozyme is degradable via phosphate; thus, mitigating potential environmental threat. This work provides novel amorphous/crystalline hetero-phase nanozymes and opens a new avenue for the design of amorphous nanomaterials and nanozymes.