Construction Of Copper Complex-based Nano-enzyme And Its Sensing Properties

In this paper,the design,synthesis,morphology and size of copper based organic complexes and their application in electrochemical/colorimetric sensing system were studied.The work is mainly carried out in the following two aspects:（1）Preparation of Cu-PDA metal-organic framework and study of glucose electrochemical biosensor based on this material.Metal-organic frameworks（MOFs）in mimetic enzymes with nitrogen-containing heterocyclic carboxylic acid ligands 1,10-phenanthroline-2,9-dicarboxylic acid（PDA）and metal copper（Cu）.Based on this,a three-dimensional rod-shaped copper based MOF was prepared by solvothermal method using PDA and divalent transition metal copper,and the material was characterized by FT-IR,XRD and XPS.The central CuⅡion coordinated with N and O atoms in PDA ligand and O atoms in water ligand in the form of pentagonal chelation.The two asymmetric units are connected to each other by carboxyl groups to form a centrosymmetric binuclear structure,and the adjacent coordination units form a three-dimensional structure throughπ-πinteraction.Subsequently,Cu-PDA MOF was applied to glucose catalysis.It was found that Cu-PDA MOF,as A novel glucose oxidation simulator,could effectively oxidize glucose.The detection limit of glucose was 0.393μM,and the sensitivity was 8.4μA/m M（0.0084μA/μM）.The linear range is 10-9800 mΜ.（2）Preparation of Cu PDA-Copper phosphate hybrid nanoflower and study of hydrogen peroxide colorimetric biosensor based on this material.Using the organic-inorganic hybrid nanoflower technology for reference,PDA and copper ion coordination were used to form Cu PDA nanoparticles to simulate peroxidase and replace the traditional natural enzyme.Cu PDA-Cu₃（PO₄）₂ HNFs was synthesized by one-pot method at room temperature,the growth mechanism of Cu PDA-Cu₃（PO₄）₂HNFs was discussed,and the H₂O₂ colorimetric biosensor based on this material was constructed.The structure,composition,morphology and surface electronic structure of the synthesized Cu PDA-Cu₃（PO₄）₂ HNFs were investigated by SEM,TEM,FT-IR and XPS.The results showed that Cu PDA-Cu₃（PO₄）₂ HNFs were stratified as flower-like microspheres with a highly dispersed size of 10-15μm.The active sites of Cu PDA nanoparticles were exposed on the surface of the nanopetals.The catalytic activity of Cu PDA-Cu₃（PO₄）₂ HNFs was twice that of Cu₃（PO₄）₂.The developed colorimetric biosensor has excellent selectivity for the determination of H₂O₂.The current range of colorimetric sensor is 10-800μM,5-30 m M,and the detection limit is 3.08 m M.