Stabilizing Ultrasmall Ceria-Cluster Nanozyme for Antibacterial and Antibiofouling Applications.

The generation of undesired biofouling in medical and engineering applications results in a reduction in function and durability. Copying functionalities of natural enzymes to combat biofouling by artificial nanomaterials is highly attractive but still challenged by the inferior catalytic activity and specificity principally because of low densities of active sites. Here, an innovate strategy is demonstrated to stabilize high-density ultrasmall ceria clusters on zirconia for biofouling prevention. Benefiting from the unique structure, CeO2 @ZrO2 nanozyme can significantly enhance the haloperoxidase-mimicking activity in catalyzing the oxidation of bromide with H2 O2 into biocidal hypobromous acid as a result of abundant defects and surface strong acidity sites, inducing impressive antibacterial and antibiofouling capacity compared with that of pristine CeO2 . This work is expected to open a new avenue for the rational design of cluster catalysts for various targeting catalytic applications.

Atomic Chromium Coordinated Graphitic Carbon Nitride for Bioinspired Antibiofouling in Seawater.

Artificial nanozymes exerting enzyme functionality are recognized as promising alternatives of natural enzymes in biomimetic chemistry. Natural haloperoxidases that utilize hydrogen peroxide (H2 O2 ) to catalytically convert halide into strong biocidal hypohalous acid hold great promise for thwarting biofouling, while their practical application remains highly questionable as instability of natural enzymes and inadequate H2 O2 . Herein a semiconducting nanozyme consisting of chromium single atoms coordinated on carbon nitride (Cr-SA-CN) that performs bifunctional roles of nonsacrificial H2 O2 photosynthesis and haloperoxidase-mimicking activity for antibiofouling is constructed. Such nanozyme is capable of generating H2 O2 from water and O2 upon visible-light illumination, and then sustainably self-supplying H2 O2 for haloperoxidase-mimicking reaction in a sequential manner. This dual-activity Cr-SA-CN overcomes H2 O2 dilemma and yields hypobromous acid continuously, inducing remarkable bactericidal capability. When used as an eco-friendly coating additive, it is successfully demonstrated that Cr-SA-CN enables an inert surface against marine biofouling. Thereby, this study not only illustrates an attractive strategy for antibiofouling but also opens an avenue to construct valuable nanoplatform with multifunctionality for future applications.