Construction of copper-functionalized two-dimensional zeolitic imidazole framework-7 (ZIF-7) nanosheets for enhanced antibacterial and antibiofilm performance

Marine biological pollution restricts the sustainable development of marine economy. Cu 2 O stands as a predominant antifouling agent for developing marine resources engineering. However, the problems of easy aggregation, rapid failure, and explosive release of copper ions limit the practical application of Cu 2 O. In this work, a novel copper-functionalized two-dimensional zeolitic imidazolate framework-7 nanocomposites ZIF-7@Cu 2 O was successfully fabricated by in-situ growth methodology. The emergence of ZIF-7@Cu 2 O nanocomposites solves the above problems in the use of Cu 2 O. Due to the huge specific surface area of the 2D ZIF-7 nanosheets and the electrostatic interactions, the cubic Cu 2 O, with a diameter of 250 nm, can be uniformly and firmly anchored on the surface of 2D ZIF-7 nanosheets, thus effectively avoiding the rapid dissolution of cuprous oxide and reducing the release rate of copper ions. Antibacterial experiments demonstrate that, in comparison to ZIF-7, Cu 2 O, and ZIF-7/Cu 2 O (physical mixture of ZIF-7 and Cu 2 O), ZIF-7@Cu 2 O exhibits superior antibacterial properties with 99.99 % against E. coli and the minimum inhibitory concentration (MIC) of 32 μg/mL. Furthermore, the reactive oxygen species (ROS) assay confirms ZIF-7@Cu 2 O could promote the generation of ROS. Antibiofilm formation results reveal that ZIF-7@Cu 2 O nanocomposites are effective in preventing biofilm formation of E. coli and P. aeruginosa at a low concentration (50 μg/mL). Finally, ZIF-7@Cu 2 O nanocomposites are employed as fillers to prepare ZIF-7@Cu 2 O/EP composite coating, the bactericidal kinetics and bacterial adherence on the coating surface are investigated. We believe this work could provide novel insights into the rational design of 2D ZIF-based material in the field of antifouling.