Post-Modification Of Zirconium-Based Metal-Organic Frameworks And The Sensing Of Hydrogen Peroxide

Hydrogen peroxide（H₂O₂）,as a second messenger,is involved in mediating basic biological processes,but excessive H₂O₂ can cause toxic and side effects on cells and their surroundings.The abnormal production of H₂O₂ in cells is often closely related to some more serious pathological conditions,such as cancer,diabetes,aging,and neurodegenerative diseases.In addition,the detection of H₂O₂ is also an indirect detection of some biomarkers to diagnose diseases such as diabetes,gout,lactic acidosis and obesity.Therefore,the accurate detection of H₂O₂ is of great significance for the diagnosis and treatment of many diseases.Metal-Organic Frameworks（MOFs）have a periodic pore structure,high specific surface area,and rich active sites,which enable the pre-concentration of the substance to be measured,and improve the contact efficiency between the substance and the frame structure.MOFs have now realized the detection of various analytes including ions,biological molecules,nitro explosives,gas molecules,etc.The synthesis of MOFs has a certain designability.However,it is still a great challenge to directly obtain the target functional characteristics of MOFs.With the development of MOFs,post-synthetic modification（PSM）has become an effective and flexible way to solve this problem.UiOs series zirconium-based MOFs have been widely concerned because of their excellent water stability,thermal stability,and good acid and alkali resistance.Their excellent stability provides good conditions for subsequent PSMs.Quenching fluorescence detection is susceptible to external interference.Therefore,fluorescence-enhanced detection is more preferred in practical application scenarios.Therefore,it is designed to chelate rare earth Tb³⁺ions through carboxyl groups on UiO-66-（COOH）₂,and then grow silver nanoparticles（AgNPs）on the surface by tannic acid reduction method.Since H₂O₂ can oxidize AgNPs to form some Ag⁺ions,Ag⁺ions can enhance the luminescence of rare-earth ions by improving the energy transfer efficiency of the ligand to the rare-earth ions,and realize the fluorescence-enhanced detection of H₂O₂,which provides new ideas for the detection of H₂O₂.Chemiluminescence has the advantages of no external excitation light source,high sensitivity and simple operation.Among them,the lumino-hydrogen peroxide system is the most widely used,but in the absence of a catalyst,lumino and hydrogen peroxide react slowly and have weak emission.Therefore,UiO-67-bpydc is used as a platform to design the chelation of Co²⁺ions on the pyridine group of the ligand,and then load luminol in the MOF channel,thus combining the advantages of both MOFs and chemiluminescence,so that the enhanced chemiluminescence achieves the detection of H₂O₂.Since H₂O₂ is also a glucose oxidation product,the synthesized luminol,Co²⁺@UiO-67-bpydc material can also be used for glucose detection,which has potential application value for the diagnosis of diabetes and other related diseases.