Application Of Iron-based Metal-organic Frameworks As Mimetic Peroxidase

Natural enzymes involved in every aspect of our life process, its importance is self-evident. Since the natural enzyme has strong specificity, efficient catalytic and good efficiency, it is widely used in all kinds of aspects in health care,agriculture and so on. But there are also some disadvantages in natural enzymes, such as: poor instability and high cost. In order to solve the disadvantages, the peroxidase mimetic have appeared. Since 2007, iron oxide nanomaterials exhibit peroxidase activity, and then the researchs of peroxidase are increasing, the ferrous metal-organic framework is one of them. They exhibited peroxidase activity and using the properties of the enzyme to oxidized reaction substrate, it have a good effect in biochemical analysis and the removal of environmental pollutants. So we use different methods to synthesis different metal organic frameworks, and making the application of biochemical analysis as well as in dye wastewater, such as the degradation of methylene blue(MB) and Rhodamine B(Rh B). The research results are as follows:(1) In this paper, a uniformity size MOFs was synthesised, and it is confirmed by the SEM and XRD. Through the catalysis experiment, it possessed the peroxidase-like activity and could catalyze the 3, 3, 5, 5-tetramethylbenzidine(TMB) by the H2O2, changing the color of the solution to blue. Kinetic analysis demonstrated that it follow the ping-pong mechanism. In addition, the resulting detection of actual serum is in the standard deviation value range. Besides, as the new peroxidase mimic, it provide a simple, sensitive and selective method for the glucose detection. The linear range from 0.75-50 μM, as low as 0.75 μM can be detected. So, the potential of the NH2-MIL-101(Fe) is promising in the future.(2) It is proved that MOF-235 has peroxidase activity in the presence of H2O2, and it is characterized by XRD, SEM, FT-IR. And then it is used for organic dye methylene blue(MB) degradation. We investigate affecting factors, such as temperature, pH and concentration of materials. The results show that when the MOF-235 as mimetic peroxidase catalyst in the presence of H2O2 for degradation, it has a wide pH range(3-10) and within a short time, which that MB is effectively degraded(50 min), the TOC removal rate is between 50-60%. Besides it has good heat resistance and stability. In addition, under optimal conditions, we conducted a study of the reaction system dynamics and isotherms. We found that it fit second-order kinetics and Langmuir model. Finally, we discuss the possible mechanism of the degradation of methylene blue.(3) In this paper, we synthesized MIL-101(Fe) by the method of microwave method. It is characterized by means of XRD、FT-IR、SEM. Besides the MIL-101(Fe) is used as enzyme catalyst for organic dye Rhodamine B(Rh B) degradation. It was found that, the MIL-101(Fe) effectively degraded organic dyes-rhodamine B in a wide pH range within 60 min, and the removal rate can almostly reach 100%. And it had less dissolved iron content. At the same time, we carry a kinetic and isotherm equation, we found that it is fitted pseudo-second order kinetic and Langmuir model. In summary. In addition, we also investigated the mechanism of the experiment. In summary, MIL-101(Fe) could be a potential material in the degradation of sewage and waste applications.