Many medical and chemical applications require the precise supply of antimicrobial components in a controlled manner at the location of mature biofilm deposits. This work reports a facile strategy to fabricate nanoscale metal-organic frameworks (NMOFs) coencapsulating the antibacterial ligand (lysine carbon dots, Lys-CDs) and targeted drug (folic acid, FA) in one pot to improve antibiofilm efficiency against established biofilms. The resulting products are characterized by transmission electron microscopy, field-emission scanning electron microscopy, powder x-ray diffraction, and ultraviolet-visible spectroscopy. The results show that Lys-CDs could coordinate with Zn²⁺ and the adding of FA inhibits the coordination of Lys-CDs with central ions of Zn. The Lys-CDs and FA are successfully exposed with the NMOFs disintegrating in the acid environment of bacterial metabolites. We are surprised to find a sharp increase of reactive oxygen species (ROS) inside the bacterial cells by FA functionalizing NMOFs, which undoubtedly enhance the antibacterial and antibiofilm activity. The as-synthesized ZIF-8-based nanocomposites also show the peroxidase-like activity in an acid environment, and produce extremely active hydroxyl radicals resulting in the improved antibacterial and antibiofilm activity. The possible mechanisms of antibacterial activities indicate that the presence of FA is significant in the sense of targeting bacteria. This study shows a novel approach to construct acid stimulation supply system which may be helpful for the research of antibiofilms.

许多医疗和化学应用需要在成熟生物膜沉积物的位置以受控方式精确供应抗菌成分。这项工作报告了一种简单的策略来制造纳米级金属有机框架（NMOFs），将抗菌配体（赖氨酸碳点，Lys-CDs）和靶向药物（叶酸，FA）共同封装在一个锅中，以提高针对已建立生物膜的抗生物膜效率。所得产品通过透射电子显微镜、场发射扫描电子显微镜、粉末 X 射线衍射和紫外-可见光谱进行表征。结果表明Lys-CDs可以与Zn ^{2+ 配位}FA的加入抑制了Lys-CDs与Zn中心离子的配位。Lys-CDs 和 FA 成功地暴露于 NMOFs 在细菌代谢物的酸性环境中分解。我们惊讶地发现，通过 FA 功能化 NMOF，细菌细胞内的活性氧 (ROS) 急剧增加，这无疑增强了抗菌和抗生物膜活性。合成的基于 ZIF-8 的纳米复合材料在酸性环境中也表现出类似过氧化物酶的活性，并产生极其活跃的羟基自由基，从而提高抗菌和抗生物膜活性。抗菌活性的可能机制表明，FA 的存在在靶向细菌的意义上具有重要意义。