Preparation And Sensing Application Of MOFs-derived Porous Metal Oxide Nanozymes

MOFs-derived metal oxide materials have attracted widespread attention in the fields of gas storage,drug delivery,energy conversion,catalysis and chemical sensing.MOFs as a new template can be directly calcined to form bimetallic or hollow metal oxides,the preparation method is simple and efficient,and the porous metal oxide material has high porosity,high catalytic activity,good biocompatibility and response stability.In this paper,MOFs-derived bimetallic or hollow metal oxides were used as carriers to prepare high-performance nano-hybrid materials.Due to the simulated enzyme activity of nano-hybrid materials,it can be easily and sensitively detected by electrochemistry,UV and other analytical methods.It provides new ideas and methods for the design and preparation of multifunctional nanomaterials and their applications in biological analysis and other fields.In this paper,an artificial enzyme cascade system and colorimetric and electrochemical biosensors are constructed based on the porous metal oxide materials derived from MOFs.The main research contents are as follows:1.Enzyme cascade platform based on MOFs-derived bimetallic oxides for colorimetric detection of glutathione and glucoseThe bimetallic Co Mn-MOF-74 was used as the precursor and calcined at 300°C for thermal decomposition into the corresponding bimetallic oxide Mn Co₂O₄.Compared with single metal oxides,bimetallic oxides have hierarchical pores,high stability and high catalytic activity.Using Mn Co₂O₄as a carrier,platinum nanoparticles were introduced to the surface of Mn Co₂O₄to form the corresponding BSA-Pt NP/Mn Co₂O₄nanohybrid materials.We build a high-performance organized artificial enzyme cascade platform based on it.BSA-Pt NP/Mn Co₂O₄nanohybrid materials have oxidase-like and peroxidase-like activities.On the one hand,they can directly catalyze the discoloration of TMB and can be used for colorimetric detection of glutathione.On the other hand,it can catalyze TMB discoloration in the presence of H₂O₂and is used for colorimetric detection of H₂O₂.In addition,BSA-Pt NP/Mn Co₂O₄nanohybrid materials can stabilize glucose oxidase and realize the visual detection of glucose.2.Dual channel homogeneous biosensor based on Pt NP/Co₃O₄hollow polyhedral nanozyme for the detection of prostate specific antigenCo-MOF-74 with a hollow structure is prepared by hydrothermal method based on Co-MOF.Using Co-MOF-74 as a new template,it is thermally decomposed into hollow metal oxide Co₃O₄by high-temperature calcination.Compared with other metal oxides,hollow metal oxide Co₃O₄has a larger surface area,higher porosity and catalytic activity,good biocompatibility and response stability.Pt NP and Co₃O₄are combined to form the corresponding hollow nanopolyhedron composite Pt NP/Co₃O₄.The two aptamer chains of the prostate-specific antigen(PSA)were respectively modified on the surface of magnetic beads and hollow nanopolyhedron composite Pt NP/Co₃O₄as separation probes and signal probes,when incubated with the target substance PSA,the aptamer specifically recognizes PSA and forms a sandwich structure in a homogeneous solution.The sandwich structures can be separated from the mixture by the magnetic effect of the magnetic beads and catalyze the redox reactions between H₂O₂and TMB,generating quantitative electrochemical and colorimetric responses in homogeneous solution simultaneously.