Nanoparticle @MOFS Composites Simulate The Study Of Bioperoxidases

This paper mainly focus on the preparation of nanoparticles and metal-organic framework materials and the properties of the peroxidase.Natural peroxidase is ubiquitous in the biological world,and all living things depend on enzymes to carry out their life activities.It is a polymer material with biological catalytic function,the history of its research and application has been more than 200 years.As a kind of biological catalyst,biological peroxidase has high catalytic efficiency and specificity.These advantages make it have a wide range of applications in medicine,industry and environmental analysis.However,the natural enzyme has some disadvantages and limitations,such as difficulty in separation and purification,low structural stability,high price,easy to lose biological activity and inconvenience of storage and use.Therefore,nano-materials simulation of biological peroxidase have become a target for people to seek.Metal-organic frameworks（MOFs）as a new type of porous material with the specific surface area,adjustable pore structure,high diversity and some excellent characteristics have developed rapidly in recent years and become the ideal material for biological enzyme simulation system.In this airtical,we synthesized three Fe（Ⅲ）-MOFs materials MIL-n（n = 88A,88B,88B-NH2）and a Cu（II）-MOFs materials MOF-199,through the load variety of nanoparticles such as Fe₃O₄,Pt,Au and so on.We synthesized different MOFs composites successfully.For Fe₃O₄@MOF-199 materials,Fe₃O₄@Cu/C and Fe₃O₄@CuO/Cu₂O are obtained by controlling different calcination conditions.The peroxidase-like activity of Fe（Ⅲ）-MOFs materials and Cu（II）-MOFs and its derivative composites were evaluated by the catalytical oxidation of peroxidase substrate 3,3’,5,5’-tetramethyl-benzidine（TMB）.The results shows that the MOFs derivative composites have excellent peroxidase-like activity.It was found that Fe₃O₄@CuO/Cu₂O and Fe₃O₄@Cu/C derived from Fe₃O₄@MOF-199 have higher peroxidase-like activity,and the former is higher than that of the latter.So we analyzed the effects of pH,temperature（T）and H₂O₂ concentration on the biological activity of the material.It is found that the en zymatic activity of Fe₃O₄@Cu/C was highest at pH=2.5,T=50℃,and CH₂O₂=8 mM,respectively.The simulation peroxidase kinetics results show that Fe₃O₄@MOF-199 and its derived composite in accordance with typical Michaelis dy namic equation.The Km values of Fe₃O₄@Cu/C with H₂O₂ and TMB as substr ates were less than Fe₃O₄@CuO/Cu₂O,which shows that Fe₃O₄@Cu/C has a st rong affinity for substrate.Fe₃O₄@MOF-199 and its derivative composite materials were successfully used for catalytic degradation methylene blue（MB）.Under the condition of 80℃,0.05 mg/mL Fe₃O₄@Cu/C completely degradate the methylene blue within 5 min.Compared with other MOFs composites materials,it has a stronger catalytic degradation abilityand great potential applications in the analysis and detection of environmental organic pollutants.