| Metal-organic Frameworks（MOFs）are composed of Metal ions or Metal clusters and organically linked ligands by coordination bonds.MOFs have been widely used in gas storage,gas adsorption and separation,catalysis,drug delivery and other fields due to the characterizations of their structural diversity,highly ordered porosity,tunable pore size,large specific surface area,functionalization,good biocompatibility and biodegradability.Fluorescence sensors based on MOFs have been a hot research topic in recent years,mainly including ions sensing in solution,sensing of volatile substances and gases,sensing of biological signal molecules and so on.UiO-type MOFs materials have been reported in recent years.Due to their high chemical stability and thermal stability,they have attracted great attention once reported.Especially,UiO-66-NH2 has become the focus because of the amino group in the structure of UiO-66-NH2,which is easy to be functionalized.This paper aims to develop new fluorescent MOFs materials,by introducing the required functionalization into UiO-66-NH2,and study their applications in recognition and detection of biological signal molecules.The research work of this thesis mainly includes the following four aspects:（1）Hydrogen sulfide（H2S）is a vital signal molecule associated with lots of diseases,which has a huge influence on the physiological and pathological processes of the organisms.Cysteine（L-Cys）is a component of proteins and crucial metabolites.Hence,H2S and L-Cys are selected as detection objects,which possess of sulfhydryl groups.A new fluorescent material UiO-66-NH-BQB was prepared through the post-synthetic modification（PSM）,which was used for the identification and detection of H2S and L-Cys.The results showed that UiO-66-NH-BQB could quantitatively determine the concentration of H2S solution and had a good selectivity to L-Cys.The cytotoxicity test showed that the UiO-66-NH-BQB had no effect on the cell morphology and had good biocompatibility.The proposed UiO-66-NH-BQB probe is a promising candidate for recognition and measure of biothiols in biological systems.（2）As an important kind of reactive oxygen species（ROS）and an indispensable signaling molecule,hydrogen peroxide（H2O2）plays an irreplaceable role in many pathophysiological events in the organisms.Hence,it is necessary to develop a novel probe for effectively monitoring H2O2 distribution and concentration in living systems.In this study,a metal-organic framework UiO-66-NH2@B（OH）2 was successfully prepared by one-step synthesis method and acted as a novel fluorescence probe for H2O2 recognition and detection.The fluorescence signals were enhanced greatly when the UiO-66-NH2@B（OH）2 was exposed to H2O2,showing high selectivity and sensitivity to H2O2.Moreover,the UiO-66-NH2@B（OH）2 probe could be used for quantitative determination of H2O2.Attributing to the excellent biocompatibility,the UiO-66-NH2@B（OH）2 is recommended as a promising fluorescence probe to recognize,detect and monitor H2O2 in vivo.（3）Sialic acid（SA）is a crucial component of glycoproteins and glycolipids on the cellular membrane,which is essential for maintaining the function of cell membranes.Simultaneously,sialic acid plays a significant role in many physiological and pathological processes.Based on the previous work,boronic acid functionalized metal-organic frame material UiO-66-NH2@B（OH）2 was used to determine sialic acid.The results showed that the UiO-66-NH2@B（OH）2 probe had a good selectivity for sialic acid and could quantitatively determine sialic acid with the detection limit as low as 0.025 mmol/L.Particularly,the content of total sialic acid in mouse serum samples could be determined accurately by the UiO-66-NH2@B（OH）2 probe.Therefore,the developed UiO-66-NH2@B（OH）2 has a good practical application in the detection of sialic acid.（4）The greenhouse effect causes global warming,which has caused a serious threat to human beings,animals and plants.The most important cause of the greenhouse effect is the massive emission of carbon dioxide（CO2）.Carbonic anhydrase（CA）is considered as a green catalyst for carbon dioxide biomineralization.However,the fragile nature of the enzyme in the application environment greatly limits its industrial application.In this study,through the comparative study of the enzyme loading and activity of enzyme loaded on several materials,the UiO-66-NH2/GO composite material was finally screened out,which was composed of the hydrophilic two-dimensional structure of graphene oxide（GO）and UiO-66-NH2.It was also found that the stability of CA on UiO-66-NH2/GO was greatly improved.This study provides a composite material which can load CA and enhance its stability,and provides a method for the practical application of carbonic anhydrase. |
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