The Research Of Optical Sensor Based On Metal Organic Frameworks Materials

Metal-organic frameworks?MOFs?are an emerging class of highly ordered crystalline porous materials that have attracted great attention and rapid development.Due to the large surface areas,uniform but tunable cavities and intriguing functionalities,MOFs have been considered as promising materials to be suitable for a broad range of applications,including catalysis,gas storage,drug delivery,chemical sensing and pollutants separation.Among them,lanthanide functionalized metal organic frameworks?Ln-MOFs?have been extensively studied.They have unique optical properties including high strength,large Tokes shift,the visible color of visible light and the relatively long lifetime of luminescence.Nnanoentities?NEs?@MOFs composites also have attracted attention that there are not only unique properties of nanomaterials and MOFs but also their unique synergistic functions.In this dissertation,Lanthanide functionalized metal organic frameworks?Ln-MOFs?and two kinds of composite materials based on UIO-66-NH₂ functionalization were synthesized and studied their applications in optical sensors.The details are as follows:Chapter 1 OverviewIn this chapter,Lanthanide metal organic frameworks and the characteristics of NE@MOF composite materials are mainly introduced and optical sensing is constructed and applied to the environment,life and other fields.Finally,the research content and significance of this thesis are expounded.Chapter 2 Boric-Acid-Functionalized Nanoscale Tb-Metal-Organic Frameworks for Scavenging Reactive Oxygen Species within living cellsThis paper aims to develop a lanthanide MOFs sensing system with excellent fluorescence characteristics.The synthesis of Tb-MOF is self-assembly with3,5-Dicarboxybenzeneboronic acid as a ligand,rare-earth luminescence terbium ions as metal ion,which has a free boronic acid group that can be used to adjust the energy level of the ligand and then adjust luminescence intensity of rare earth ions from the the luminescent center of Tb-MOF by antenna effect.In addition,when the ROS is present,an affinity addition reaction occurs with the free boronic acid group,so that reduced the luminescence of the rare earth luminescence center emitting by the antenna effect.Therefore,Tb-MOF can be used as a scavenger of reactive oxygen species.With the increase of ROS concentration,Tb-MOF reacts with ROS to change the energy level of the ligand and then regulated the fluorescence intensity of Tb-MOF.Chapter 3 Platinum Nanoparticle Encapsulated Metal-Organic Frameworks for Colorimetric Measurement and Facile Removal of Mercury?II?In this work,UiO-66-NH₂ as a unique host matrix offers a platform to generate Pt NPs@UiO-66-NH₂ composites with synergistic effect by encapsulate pre-synthesized PVP-Stabilized Pt NPs into MOFs.Moreover,the specific interaction between Hg²⁺and Pt NPs leads to the effective suppression of the peroxidase-like activity of Pt NPs@UiO-66-NH₂,which endows excellent selectivity for Hg²⁺measurement over the interfering metal ions.Based on the colorimetric sensing system,Hg²⁺is linearly measured over the range from 0 to 10 nM with a detection limit of 0.35 nM.Moreover,the as-obtained Pt NPs@UiO-66-NH₂ nanocomposites exhibit high adsorption capacity for Hg²⁺,which is successfully applied to treat Hg²⁺in water with removal efficiency over 99%.Chapter 4 PPi triggered disassembly of RhB-encapsulated UIO-66-NH2composite for PPi measurementIn this paper,one-pot method was used to synthesize RhB@UiO-66-NH₂ and then the stability of the composite in aqueous solution and the conditions of destroying the host matrix in the presence of the target were investigated.Due to the small volume and the strong affinity of pyrophosphate?PPi?with the metal ions in UiO-66-NH₂,the RhB@UiO-66-NH₂ composite was triggered to disintegrate and rapidly released RhB in the presence of PPi.