Synthesis And Application Study Of Triphenylamine-based Fluorescent Materials

Recently,fluorescent probes has attracted much more attention of chemistry and material researchers for its high sensitivity and easy handleability in molecular/ion recognition,bio-imaging,medical treatment and biological molecular detection.In most fluorescent chromophore,triphenylamine?TPA?,which is a common propelle-like geometry,is widely used in photoelectric materials and hole-transporting materials due to its larger steric hindrance factors,super conjugate electronic effect and high hole mobility.The three benzene rings linked with the nitrogen atom of triphenylamine,with its high activity,structural diversity and easily modified characteristics,can be connected with external different functional groups at appropriate positions and a series of luminescent materials with specific functions can be produced,which can be applied to molecular/ion recognition,bio-imaging and etc.In the field of cell imaging,as the cells genetic and metabolic regulation and control center and cell energy device,nucleolus and mitochondria play an important role in cell growth,proliferation,and apoptosis.Obviously,chronically observing changing processes of the nucleus and mitochondria through fluorescence molecular imaging localization has important significance in monitoring and treatment of disease,drug development and gene science and other fields.The triphenylamine and its derivatives as well as general commercial dyes have many shortcomings,respectively.Firstly,most of triphenylamine and its derivatives exhibit typical Aggregration-Caused-Quenching?ACQ?effect which mainly caused by the large conjugation structure is easily self-assembly through?-?stacking.triphenylamine and its derivatives have a poor solubility in water,which limited their widely applications.Thus,it is of great significance to convert triphenylamine and its derivatives from ACQ to AIE with a good solubility in water.Secondly,up to now,the commercially available dyes of nucleus and mitochondria?DAPI,Hoechst,Mito-Tracker?have defects in practical application,such as a low photostability,high toxicity and tracking without long-term.However,the long-term nucleus tracking and simultaneously staining different organelles by single probe with distinct colors remain as great challenge.Thus,there's a great significance and value to synthesize a kind of target molecules for nucleus and mitochondria that have good photostability and biocompatibility,and can be used to long-terms cellular tracing.According to the properties,series of fluorescence probes have been synthesized via taking TPA as matrixes in this paper.On the one hand,NBTA molecules are synthesized by Vilsmeier Heck coupling reaction and hydrolysis reaction.It can detect picric acid?PA?based on supramolecular complex system with SiO₂-KH550 and visually sense CO₂ and F^-with CTAC in the water solution.On the other hand,synthesized of TPPA-DBO based on TPPA and 1,8-dibromooctane?DBO?in DMF.We study its basic optical properties,and apply to nucleus and mitochondria imaging.The thesis consists of three parts as following:1.Taking Tris?4-iodophenyl?amine as a raw material and triacrylic acid of TPA?NBTA?have been synthesized through Vilsmeier Heck reaction.Synthesized SiO₂-KH550 by KH-550 and SiO₂ hybrid reaction,and study the UV-vis absorbance spectrum and fluorescence spectrum at different SiO₂-KH550 concentrations with NBTA.Both of them show the PL intensity originated from the more and more SiO₂-KH550.These NBTA&SiO₂-KH550 serve as highly selective and sensitive supramolecular polymer fluorescent probes for picric acid?PA?in EtOH and The detection limit were determined?300 ppb?.The system is an outside stimulus signal amplification system,and can be destroyed with trace PA,which shows great fluorescence intensity changes in the macroscopic aspects.2.It is a problem that NBTA solutes poorly in water,NBTANa(NBTA^3-)which can solutes in water was synthesized by NaOH and NBTA.NBTA forms ionic liquids with CTAC through electrostatic interaction,and can visually sense CO₂ and F^-in the water solution by ion exchanging.In the solution,CO₂ from human breath can weaken fluorescence,and occur an obvious red shift,which explains that we can visually sense trace CO₂.In our research work,we prepared the NBTA^3-/CTAC doped hydrogels using gelatin as scaffold materials,therefore,the sensitive visualized exhibitions could be realized when F^-takes a very low concentration of 0.032 eqvi.3.We grafted the Triphenylamine derivative DNDT into SiO₂-NH₂ to prepare functionalized materials and form DNDT&SiO₂-NH₂ nanoparticles.The DNDT&SiO₂-NH₂@BSA system was formed by the DNDT&SiO₂-NH₂ biological macromolecule,with BSA as the coating material.Biological macromolecules have good solubility and biocompatibility,and under the temperature stimulation?-helix changes can release the coating.Therefore,we use the temperature as an external stimulus to achieve the purpose of drug release,and completed the drug's long-term sustained release to 11 h under the human body temperature4.TPPA-DBO is synthesized based on TPPA and 1,8-dibromooctane?DBO?in DMF,with good photostability,biocompatibility,higher fluorescence quantum yield,low cell toxicity,and small particle size.The UV-vis absorbance spectrum and fluorescence spectrum show that TPPA-DBO typically display aggregation-induced emission?AIE?,which can detect trace DNA and RNA.Finally,this probe is used as tracer agent for different cell imaging.Due to the blue shift after combines with DNA and RNA,and having no changes after combines with mitochondria proteins,it can dye nucleus and mitochondria with different colours,which solves the problem that dyes and targets different organelles.The result shows that this molecule can stay in cells for a long time?at least 4passages?,making the water soluble AIE molecule for long-term cellular organelles tracing applications come true.