Double enzyme mimetic activities of multifunctional Ag nanoparticle-decorated Co3V2O8 hollow hexagonal prismatic pencils for application in colorimetric sensors and disinfection

Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes, there is urgent need to discover novel highly efficient enzyme-like materials. In this work, Co₃V₂O₈ with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme mimics. They were then decorated by photo-depositing Ag nanoparticles (Ag NPs) on the surface to further improve its catalytic activities. The Ag NPs decorated Co₃V₂O₈ (ACVPs) showed both excellent oxidase- and peroxidase-like catalytic activities. They can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue change. The enhanced enzyme mimetic activities can be attributed to the surface plasma resonance (SPR) effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co₃V₂O₈, accelerating electron transfer and promoting the catalytic process. ACVPs were applied in constructing a colorimetric sensor, validating the occurrence of the Fenton reaction, and disinfection, presenting favorable catalytic performance. The enzyme-like catalytic mechanism was studied, indicating the chief role of ⋅O₂^- radicals in the catalytic process. This work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.