Design And Synthesis Of Functional Metal-Organic Frameworks And Their Applications In Biology

Metal-organic frameworks（MOFs）are surprisingly porous materials whose excellent properties such as excellent chemical modifiability,large specific surface area,abundant porosity,and tunable pore structure make them widely used in catalysis,gas adsorption,drug delivery,and electrochemical sensing.In this paper,starting from the electrochemical sensing analysis of drugs and antibacterial requirements,the design,synthesis,structure and performance of functional MOFs in drug sensing analysis and antibacterial applications are studied.The main contents are as follows:（1）Hemin-doped-HKUST-1 nanoenzyme material was prepared by substituting hemin（hemin）for part of trimesic acid in HKUST-1,and further combined with electro-reduced graphene oxide to construct an electroenzyme.Chemical sensors for sensitive detection of the neurodrug dopamine.The results show that the constructed electrochemical sensor has high sensitivity(1.224μAμM^-1),low detection limit(3.27×10^-8 M)and wide linear range（0.03-10μM）for dopamine.The sensor also has very satisfactory stability and reproducibility,and has been successfully applied to DA detection in real samples,which has potential clinical value.（2）Using three lanthanide elements（Ce,Tb,Gd）as the central atom and trimesic acid as the ligand,three MOF nanozyme materials were grown on the surface of graphene oxide by in-situ synthesis,and further Construction of an electrochemical sensor to detect dopamine.The study found that the three lanthanide MOF nanozymes have similar structures and similar properties,and all showed excellent performance in the detection of dopamine.Among them,the MOF nanozyme constructed with Ce element exhibited the best performance,and its electrical signal had a linear relationship in the range of dopamine concentration from 1×10^-8 M to 1×10^-4 M,and the current value after100 detections There is no significant decrease,showing excellent stability.（3）With Ce（IV）as the central atom and trimesic acid as the ligand,the ultrafine Ce（IV）-MOF was constructed by in-situ growth method,and the Ce（IV）-MOF/GO/GCE was further constructed.The electrode was reduced to Ce（III）/（IV）-MOF/r GO/GCE by electrochemical deposition,which was applied to the detection of anticancer drug chlorogenic acid.It is found that the coexistence of Ce（III）and Ce（IV）can significantly improve the performance of Ce-MOF,and the highest sensitivity(1.662μAμM^-1)of the sensor can be obtained at the optimal ratio,and its detection limit is as low as 1.27×10^-10M（S/N=3）.The ultrafine size of Ce（III）/（IV）-MOF endows the sensor with excellent electrical conductivity,and the extremely low Ce content further reduces the cost,enabling the sensor to be widely used in clinical work.（4）Ga-FA MOF was synthesized in aqueous solution with Ga³⁺as the central atom and fumaric acid（FA）as the ligand,and its antibacterial function was tested in Pseudomonas aeruginosa.Ga-FA MOF exhibits excellent bactericidal properties.The reason is that Ga element can replace Fe element and be taken into the body by bacteria and interfere with bacterial metabolism,leading to its death.FA,as a low-level carbon source,can increase the metabolic activity of bacteria and increase its growth rate.Large demand for Fe,there is a strong synergy between FA and Ga³⁺.And Ga-FA MOF can be decomposed faster and more fully in the presence of bacteria,reflecting the role of dual targeting mechanism.Ga-FA MOFs have extremely low cytotoxicity and can be well applied in vivo.The antibacterial material is expected to be used in clinical treatment to solve the problem of bacterial resistance.