基于金属卟啉2DMOFs仿酶催化的过氧化氢比色法检测

以四（4-羧苯基）铁卟啉（FeTCPP）作为有机配体，铜离子作为金属节点，利用溶剂热法制备了双金属Cu-FeTCPP金属有机骨架（MOFs）材料，并采用表面活性剂辅助法合成了二维纳米片（Cu-FeTCPP 2DMOFs）.该纳米片呈超薄的纳米结构，与三维块体结构（3DMOFs）相比具有更大的比表面积.基于Cu-FeTCPP 2DMOFs的仿酶特性，将其用于催化过氧化氢（H₂O₂）氧化底物3，3'，5，5'-四甲基联苯胺（TMB）显色，根据显色产物吸光度与H₂O₂浓度之间的正比关系实现了对H₂O₂的测定.经稳态动力学分析发现，底物相同时该纳米片的米氏常数K_m均比Cu-FeTCPP 3DMOFs的K_m小，表明纳米片与底物之间有更好的亲和力，这归因于二维结构大的比表面积和较多易接近的活性位点.基于Cu-FeTCPP 2DMOFs构建的比色检测方法在优化条件下对H₂O₂的线性检测范围为3~1000 μmol/L，检出限为2.08 μmol/L，在水体中H₂O₂的检测方面具有良好的应用前景.

Colorimetric Detection Method for H2O2 Based on Two-dimensional Metal-organic Frameworks of Metalloporphyrin

Using iron tetra(4-carboxyphenyl)porphyrin(FeTCPP) as the organic ligand and copper ions as the metal nodes, the metal-organic frameworks(MOFs) of bimetallic Cu-FeTCPP were prepared by solvothermal method, and the two-dimensional ultrathin nanosheets(Cu-FeTCPP 2DMOFs) were synthesized by a surfactant-assisted method. Compared with the three-dimensional bulk MOFs(3DMOFs), the nanosheets had ultra-thin nanostructures and larger specific surface area. Cu-FeTCPP 2DMOFs with enzyme-like properties can catalyze the chromogenic oxidation of the substrate 3,3',5,5'-tetramethylbenzidine(TMB) by hydrogen peroxide(H₂O₂). The proportional relationship between the absorbance of the reaction products and the concentration of H₂O₂ enabled the determination of H₂O₂. In the steady state kinetic analysis, the Michaelis constants K_m of the nanosheets were smaller than those of Cu-FeTCPP 3DMOFs, indicating that the nanosheets showed better affinity to the substrates. This is attributed to the larger specific surface area of ??the 2D ultrathin structure and the higher accessibility of active sites. The colorimetric detection method for H₂O₂ based on Cu-FeTCPP 2DMOFs had a linear detection range of 3-1000 μmol/L and a limit of detection(LOD) of 2.08 μmol/L, showing application prospects in the detection of H₂O₂ in water.