Drug Microbiology Lab, Drug Radiation Research Department, National Center for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA), Cairo, Egypt.
Department of Basic Medical Sciences, Faculty of Medicine, Galala University, Galala City 43511, Suez, Egypt.
BMC Microbiol. 2024 Nov 6;24(1):453. doi: 10.1186/s12866-024-03587-9.
Although there are many uses for metal-organic framework (MOF) based nanocomposites, research shows that these materials have received a lot of interest in the field of water treatment, namely in the photodegradation of water contaminants, and disinfection of some pathogenic bacteria and fungi. This is brought on by excessive water pollution, a lack of available water, low-quality drinking water, and the emergence of persistent micro-pollutants in water bodies. Photocatalytic methods may be used to remove most water contaminants, and pathogenic microbes, and MOF is an excellent modifying and supporting material for photocatalytic degradation.
This work involved the fabrication of a unique Cu-MOF based nanocomposite that was exposed to gamma radiation. The nanocomposite was subsequently employed for photocatalytic degradation and as an antimicrobial agent against certain harmful bacteria and fungi. The produced Cu-MOf nanocomposite was identified by XRD, SEM, and EDX. Growth curve analysis, UV lighting impact, and antibiofilm potential have been carried out to check antimicrobial potential. Additionally, the membrane leakage test was used to determine the mechanism of the antimicrobial action. In an experimental investigation of photocatalytic activity, a 50 mL aqueous solution including 10.0 ppm of Rhodamine B (RB) was used to solubilize 10 mg of Cu-MOF. It has been investigated how pH and starting concentration affect RB elimination by Cu-MOF. Ultimately, RB elimination mechanism and kinetic investigations have been carried out.
SEM images from the characterization techniques demonstrated the fact that the Cu-MOF was synthesized effectively and exhibited the Cu-MOF layers' flake-like form. Uneven clusters of rods make up each stratum. The primary peaks in the Cu-MOF's diffraction pattern were found at 2θ values of 8.75, 14.83, 17.75, 21.04, 22.17, 23.31, 25.41, and 26.38, according to the XRD data. After 135 min of UV irradiation, only 8% of RB had undergone photolytic destruction. On the other hand, the elimination resulting from adsorption during a 30-min period without light was around 16%. Conversely, after 135 min, Cu-MOF's photocatalytic breakdown of RB with UV light reached 81.3%. At pH 9.0, the greatest removal of RB at equilibrium was found, and when the amount of photocatalyst rose from 5 to 20 mg, the removal efficiency improved as well. The most sensitive organism to the synthesized Cu-MOF, according to antimicrobial data, was Candida albicans, with a documented MIC value of 62.5 µg mL and antibacterial ZOI as 32.5 mm after 1000 ppm treatment. Cu-MOF also showed the same MIC (62.5 µg mL) values against Staphylococcus aureus and Escherichia coli, and 35.0 and 32.0 mm ZOI after 1000 ppm treatment, respectively. Ultimately, it was found that Cu-MOF (1000 µg/mL) after having undergone gamma irradiation (100.0 kGy) was more effective against S. aureus (42.5 mm ZOI) and E. coli (38.0 mm ZOI).
From the obtained results, the synthesized MOF nanocomposites had promising catalytic degradation of RB dye and high antimicrobial potential which encouraging their use in wastewater treatment against some pathogenic microbes and polluted dyes. Due to the exceptional physicochemical characteristics of MOF nanocomposites, it is possible to create and modify photocatalytic nanocomposites in a way that improves their recovery, efficiency, and recyclability.
尽管金属有机骨架（MOF）基纳米复合材料有许多用途，但研究表明，这些材料在水处理领域，特别是在水污染物的光降解和某些致病细菌和真菌的消毒方面引起了广泛关注。这是由于过度水污染、可用水资源短缺、劣质饮用水以及水体中持久性微污染物的出现造成的。光催化方法可用于去除大多数水污染物和致病微生物，而 MOF 是光催化降解的极好的修饰和支撑材料。
本工作涉及制备一种独特的铜基 MOF 纳米复合材料，该复合材料经伽马辐射处理。随后，该纳米复合材料被用于光催化降解和作为某些有害细菌和真菌的抗菌剂。通过 XRD、SEM 和 EDX 鉴定了所制备的 Cu-MOF 纳米复合材料。进行了生长曲线分析、UV 光照影响和抗生物膜潜力测试，以检查抗菌潜力。此外，还使用膜泄漏测试来确定抗菌作用的机制。在光催化活性的实验研究中，使用 50 mL 含有 10.0 ppm 若丹明 B（RB）的水溶液来溶解 10 mg 的 Cu-MOF。研究了 pH 值和起始浓度如何影响 Cu-MOF 对 RB 的去除。最终，对 RB 的消除机制和动力学进行了研究。
从表征技术的 SEM 图像可以看出，Cu-MOF 的合成是有效的，并且显示了 Cu-MOF 层的片状形式。每个地层由不均匀的棒状簇组成。Cu-MOF 的衍射图案中的主要峰出现在 2θ 值为 8.75、14.83、17.75、21.04、22.17、23.31、25.41 和 26.38 处。根据 XRD 数据。在 135 分钟的 UV 照射后，只有 8%的 RB 经历了光解破坏。另一方面，在没有光照的 30 分钟吸附期间，消除率约为 16%。相比之下，在 135 分钟后，Cu-MOF 在 UV 光下对 RB 的光催化分解达到了 81.3%。在 pH 9.0 时，在平衡时发现 RB 的去除率最高，当光催化剂的用量从 5 增加到 20 mg 时，去除效率也有所提高。根据抗菌数据，对合成的 Cu-MOF 最敏感的生物体是白色念珠菌，MIC 值为 62.5 µg mL，在 1000 ppm 处理后抗菌 ZOI 为 32.5 mm。Cu-MOF 对金黄色葡萄球菌和大肠杆菌也表现出相同的 MIC（62.5 µg mL）值，在 1000 ppm 处理后 ZOI 分别为 35.0 和 32.0 mm。最终发现，经过伽马辐射（100.0 kGy）处理后的 Cu-MOF（1000 µg/mL）对金黄色葡萄球菌（42.5 mm ZOI）和大肠杆菌（38.0 mm ZOI）更有效。
从获得的结果来看，合成的 MOF 纳米复合材料对 RB 染料具有良好的光催化降解性能和较高的抗菌潜力，这鼓励它们在废水处理中用于对抗一些致病微生物和污染染料。由于 MOF 纳米复合材料的特殊物理化学特性，可以创造和修饰光催化纳米复合材料，以提高其回收、效率和可回收性。
