Formation and antibacterial performance of metal−organic framework films via dopamine-mediated fast assembly under visible light

Metal−organic frameworks (MOFs) have recently attracted intensive interest toward a variety of potential applications due to their very high porosity. However, the preparation of MOF films is tedious and involves complicated procedures. Herein, we report a simple and widely applicable strategy to fabricate uniform MOF layers on desired substrates via dopamine (DA) codeposition from neutral (pH = 7) aqueous MOF particle dispersions mediated by visible light (vis). Uniquely, DA and MOF at pH 7 under vis illumination created a synergistic condition, leading to the formation of a uniform and stable MOF layer, which otherwise appeared to be difficult to obtain. The zirconium-based MOF particle, UiO-66, played an important role in helping generate a suitable amount of reactive oxygen species under vis to promote DA polymerization, which in turn significantly facilitated the MOF film formation. By introducing rose bengal into the MOF film, excellent photodynamic antibacterial activities against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were achieved. Overall, this study provides a straightforward strategy in preparing MOF thin films on desired substrates, which may help expand the application of functionalized MOFs.