| As a material with natural enzymatic catalytic activity,mimic enzymes have the characterized of simple synthesis process,good stability and easy storage.As the substitutes for natural enzymes,mimic enzyme have been widely used in the fields of medicine,sensing,catalysis and environmental engineering in the past decades.However,due to the short development time,the mimic enzyme still has some disadvantages such as low catalytic efficiency,poor affinity with substrate and fixed research methods.Therefore,it is particularly important for the research and application of new mimic enzyme materials.Metal-organic frameworks（MOFs）are a class of porous materials formed by coordination reactions between metal/metal cluster and organic ligand.MOFs have great potential in the construction and application of mimic enzyme based on its large specific surface area,high porosity,abundant metal sites,and easy to modify functional groups.In this work,two novel MOFs were synthesized by hydrothermal method using 2-imidazol-1,4-ephthalic acid（H2L）as ligand.The mimic enzyme activity and catalytic mechanism of MOFs were explored by colorimetry and chemilunisescence method.This work was divided into the following three parts:Chapter 1:Firstly,the commonly mimic enzyme materials and research method of mimic enzyme were summarized.Then,the advantages of MOFs as mimic enzyme were elaborated,the research types of MOFs as mimic enzyme and their applications in analysis sensing were briefly summarized.Finally,based on the current research status and existing probolems of MOFs mimic enzyme,the research current and significance of this paper were proposed.Chapter 2:A novel 3D Cu-MOF was prepared by hydrothermal method using Cu I as metal source,and the structure and properties were characterized by XRD,BET,TGA and XPS.The study of mimic enzyme activity found that Cu-MOF had excellent peroxidase-like（POD）activity in acidic and alkaline conditions,which effectively promoted the TMB-H2O2color reaction and luminol-H2O2 CL reaction.The steady-state kinetic studies showed that Cu-MOF had a low km value and high affinity with H2O2,and can be used as a substitute of HRP.Meanwhile,the catalytic mechanism of Cu-MOF was studied by comparing the catalytic effect of Cu-MOF and isomorphic MOFs（Zn-MOF,Ni-MOF,and Cu-MOF（L2））.The results showed that the catalytic activity of Cu-MOF was metal ions rather than ligands,which effectively promoted free radicals in the reaction process and electron transfer.The high affinity of Cu-MOF with H2O2 made it an idea catalyst for catalyzing luminol-H2O2CL reaction.Based on the POD activity of Cu-MOF and the specificity of glucose oxidase on the substrate,a two-enzyme CL glucose detection method was constructed.The measurement results of this method were in good agreement with the results of kit.Chapter 3:A novel Co-MOF was synthesized by hydrothermal method,which exhibited a1D chain with dual-nuclear[Co2（COO）2（H2O）O]sencondary building unit（SBU）,a 3D supramolecular structure was formed by hydrogen bonding between chain and chain.TGA and PXRD data showed that Co-MOF had an excellent thermal stability and chemical stability.The spectrophotometry and CL proved that Co-MOF had superior peroxidase-like and weak oxidase-like activity.The peroxidase-like activity of Co-MOF was further studied using luminol and H2O2 as substrate,the results showed that Co-MOF had excellent affinity for luminol and H2O2.Compared with HRP,Co-MOF exhibited the catalytic activity in a wide p H（2.0～11.3）range,and its optimal catalytic conditions at p H 7.4.More importantly,Co-MOF as an enzyme-like catalyst had good reversibility and recyclability,and its catalytic activity remained unchanges after strict p H and temperatures treatment and long-time storage.Based on the inhibition of GSH on luminol-H2O2-Co-MOF CL signal,a CL method to determine the GSH content was proposed,and the detection limit was 30nmol m L-1. |
