Designing,Assembly And Application Of Rare Earth Metal-organic Framework Nanoreactors

With the continuous development of nanotechnology,research on nanoreactors has drawn more and more attention.In the general,chemical reactors are generally specific chemical equipment such as reactors or glass reactors,but nanoreactors are nanomaterials or materials with nanostructures,nanoreactors provide a nanoscale space,so that the chemical reaction is restricted in this nano-space,reaction products with specific structures and properties can be obtained by controlling the size,material,and other reaction conditions of the nanoreactor.Among them,nano metal-organic framework materials and nano layered hydroxides can be used as nano-reactors with excellent performance to ensure efficient energy transfer between materials in the pores and achieve the purpose of material design.In many metal-organic framework materials and rare earth metal-organic frameworks and rare earth layered hydroxides are not widely studied,but their unique structures and their optical properties are well worth exploring for their potential value.Recently,this type of luminescent material has received more and more attention,and has been applied in the fields of photoelectric functional materials,bioluminescent probes,biological small molecules and metal ion detection,drug transport,bioimaging,and catalysis.Rare-earth metal-organic frameworks are characterized not only by the high specific surface area of metal-organic framework materials,their adjustable pore size and easy functionalization,but also the intrinsic luminescent properties of rare earth ions,and the luminescence property of rare earth elements as nanomaterials.In the rare earth ions center,because of the luminescence originates from f-f electron transitions in the 4fn shell,its unique structure and energy level also create many special optical properties of rare earth luminescent materials,such as wide emission spectrum,long fluorescence lifetime,and the wavelength is not affected by the surrounding coordination field and environment,and therefore it can emit sharp line spectra.The dissertation is mainly divided into following three chapters:Chapter 1: A brief introduction of the research and application status of rare earth metal-organic framework materials and rare earth layered hydroxides.Chapter 2: A nanoreactor was constructed using functionalized nanoscale Eu(III)metal-organic framework compounds for near-infrared excitation and targeted two-photon absorption photodynamic therapy.Recently,nanoscale Metal-Organic Frameworks(NMOFs)and photodynamic therapy have become increasingly concerned as potential drug therapy systems.Based on the NMOFs: Eu(BTC)DMF · H2 O,the nano-probe MB@THA-NMOF@c RGD was designed and synthesized by surface modification of c RGD and the absorption of photosensitizer methylene blue(MB),achieved NIR-excited targeted photodynamic therapy.The assembling of the probe including three steps: 1.Solvent assistant ligand cooperation of NMOF-76 with 4,4,4-trifluoro-1-(9-hexylcarbazole-3-yl)-1,3-butanedione(HTHA);2.The absorption of MB;3.Surface modification of nanoparticles with c RGD.The coordination between HTHA and Eu3+ provide NMOF-76 with two-photon excited luminescence(TPL)function under near-infrared(NIR)excitation.Under the laser excitation wavelength of 808 nm,MB in the pore of NMOF-76 can be excited by the 615 nm light emission of Eu3+,resulting in singlet oxygen(1O2)generation and achieving photodynamic therapy.The surface modification with c RGD achieves the biological compatibility and the targeting,due to the overexpression of integrin ?v?3 in cancer cell.Thus,the NMOF nanoprobe can be used as a nanoscale platform for PDT therapy.The research results have certain theoretical significance and application value to the development of smart luminescent rare earth diagnostic and therapeutic probes.Chapter 3: Real-Time Monitoring of Dissolved Oxygen with Porphyrin-based Metal-Organic Materials.Luminescent metal-organic frameworks(LMOFs)as probes for the determination of dissolved oxygen(DO)concentrations are a hot topic recently.Therefore,we designed a rare earth metal-organic framework based on porphyrin derivative structure as a novel porous matrix material probe with phosphorescent response to DO.We use m-Tetrakis(4-sulfonatophenyl)porphine(TPPS)as a bridge ligand for the oxygen response center and the MOF structure,and then together with rare earth metals act as a fluorescence feedback part.The probe can adapt to harsh chemical environments,and has good light stability based on different p H environments and can accurately feedback the fluorescence intensity of DO in the system.Due to the nanopore and uniformly distributed oxygen entry sites in the MOF structure,the MOF structure exhibits a reversible fluorescence response and a good Stern-Volmer quenching relationship.