The Synthesis Of Triphenylamine-Based Fluorescence Probes And Their Applicationin Cell Imaging

As compared to other imaging methods,fluorescence imaging is low cost,easy to operate and can provide high sensitivity and high resolution images with information at subcellular levels,for which is widely used as a versatile tool for bioscience and clinical medicine.Sofar,most imaging probes are conventional organic fluorophores because of their great variety and strong emission.However,the traditional organic luminophores have their drawbacks such as the low photostability and the high cytotoxicity,which limited their application in fluorescence imaging.Therefore,new fluorescence probes that have excellent photostability,high quantum yield and low cytotoxicity must be developed.The triphenylamine molecule takes a nitrogen atom as the center to bind three benzene rings through the C-N bond.It is a propeller-type structure due to the rotation of the C-N bond.The electrophilic aromatic substitution reaction of triphenylamine easily occurs at the three para positions to form the triphenylamine derivatives.The triphenylamine-based fluorescence molecules are widely used in physical,chemical and biological sensing because of their high fluorescence quantum yield and good photostability,but there is little attention on bioimaging about these molecules.Hence,how to make the triphenylamine-based materials with good fluorescence performance widely utilized in the field of biological imaging has important implications.Accordingly,new triphenylamine-based fluorescence probes which can be used for cell imaging have been designed and synthesized in this thesis.It is composed of two parts as following:1.The TPAS molecule with double triphenylamine structures has been synthesized by means of Vilsmeier-Haack reaction and McMurry reaction.We studied the structure and photophysical properties of TPAS by ¹H NMR,¹³C NMR,FT-IR,fluorescence and UV spectrums.The results show that TPAS possesses ACQ property in dilute solution while has a bright blue emitting in solid state.Then the good photostability,favourable dispersibility,small size and low cytotoxicity make TPAS to be a desired fluorescence probe to realize high sensitivity and high resolution for application in living A549 cells imaging.2.Triphenylamine is used as a raw material to obtain compounds PDBD and NTBD,then two fluorescence polymers with donor-acceptor?D-A?structures,named LP and BP,have been synthesized via Aldol Addition and Condensation reaction which takes advantages of catalyst-free,inert gas protect-free,solvent dryness-free.The structures of the two polymers are confirmed by ¹H NMR,¹³C NMR and FT-IR spectrums.Both LP and BP have outstanding photophysical properties by studying fluorescence spectrum and UV spectrum.The restriction of intramolecular rotation?RIR?are not the same due to the flexible linear structure of LP and the rigid network of BP,thus reflecting a large difference on solubility,the solvatochromism and the fluorescence in aggregation state.Then LP is taken as a fluorescence imaging probe for its better solubility,AIEE property,low cytotoxicity and the appropriate size.The results show that LP behaves good biocompatibility and high resolution when it was used for labeling MPC5 cells.