The Electrochemical Catalytic Research Based On Functional Material Of MOF-199 And Its Compounds

Metal-organic frameworks?MOFs?is also called as porous coordination polymers?PCPs?,it is self-assembled by organic ligand and metal ion or metal ion cluster which has crystalline open-framework with permanent pores.Fundamentally,MOFs as a kind of organic-inorganic hybrid functional materials are novel,they have unparalleled advantages over traditional inorganic materials because of their brilliant features such as low density,large pore volume,tunable structures and specific pore size distribution.Recently,it has been widely used in electrochemical catalysis,electrochemiluminescence and electrochemical sensing.The porous and high specific surface area of MOFs provide more activated sites and help to support guest molecules and/or catalyze analytes directly,and the sensitivity of electrochemical detection has been improved.Therefore,MOF and its derivatives provide is a new choice for electroanalytical chemistry with modified electrode.In this work,based on the functional modification of MOF-199,the composites with different properties were prepared by hydrothermal and calcination methods,and the synthesized-materials have been used as electrode modified materials of electrochemical sensors for electrochemical analysis and detection of bioactive molecules and environmental pollutants.The main contents are summarized as follows:?1?Graphene oxide-MOF-199 composites?GO@MOF?was obtained by growing MOF-199 on the surface of GO by one-step hydrothermal synthesis.Then,the reduced graphene and copper-organometallic framework composites?rGO@MOF?were prepared by the In situ electrochemical reduction,and electrochemical sensors based on the modified electrodes of dopaminergic?DA?and uric acid?UA?were established to investigate their oxidation properties of these two substances.Determination of DA and UA mixed samples were analyzed via differential pulse method after optimizing the experimental conditions.As a result,the linear calibration curves of DA were obtained in the range of 10⁸5?M?R²=0.9927?and 250¹500?M?R²=0.9935?,and that of UA were gotten in the range of50¹000?M?R²=0.9935?.The results showed that the modified electrode has good stability and selectivity,and it is easy to control.In addition,the development of electrochemical sensors based on rGO@MOF provided a satisfactory performance for determination of DA and UA.?2?To construct a current-mode glucose electrochemical biosensor,MOF-199 crystal were grown on N-doped graphene?NGA?,then electrodeposited gold nanoparticles?AuNPs?,and it was successfully to fasten the glucose oxidase?GOD?.The electrochemical behavior of GOD/AuNPs/NGA@MOF/GCE was investigated,and it had been proved that GOD was successfully immobilized and maintained bioactivity.The I_O22 and I_glucose between 0¹.8 mM were increasing as the concentration of glucose increased,and maintained a good linear relationship of R²>0.99.However,competition mechanism between glucose and Cu?II/I?caused the decrease of the response signal after the redox reaction of glucose with GOD and AuNPs reached its limit when raising the concentration above 1.8 mM.The ratio electrochemical method was used to detected the concentration of glucose when it was higher than 1.8 mM.With the increase of glucose concentration,I_O2/I_Cuu was increased linearly,and the linear relationship of R²>0.999.It is shown that the sensitivity and precision of the biosensor was improved by the dual signal output.?3?MOF-199 was used as precursor and carbonized at high temperature under N₂atmosphere to get the copper doped porous carbon-based materials.The metal central atoms and carbon skeleton with certain spatial structure were selectively retained.A metal-inorganic?Cu-C?framework with a specific three-dimensional structure was formed.It not only retained the excellent properties of high porosity and high specific surface area of MOFs materials,but also had high electron transfer ability.At the same time,the metal of Cu in the skeleton was preserved completely,which provided possibilities of simulated laccase via electrochemical catalyzing.In this work,a rapid,simple,high sensitive and anti-jamming method of electrochemical simulated enzyme sensor based on the simulated enzyme catalyst has been developed.Besides,the laccase substrate of p-phenylenediamine?0.07¹6 mM,R²=0.9976?,o-phenylenediamine?0.2¹6 mM,R²=0.9948?and hydroquinone?0.07⁵0 mM,R²=0.9998?,catechol?0.07⁴2 mM,R²=0.9996?were successfully detected by cyclic voltammetry.