Synthesis And Research On Recognition Performance Of Fluorescent Probes Based On Triphenylamine Derivatives

The three phenyl rotors and the nonplanar structure of triphenylamine（TPA）make it an ideal building block for aggregation-induced emission（AIE）group,and the triphenylamine group can also be used as an electron donor to synthesize fluorescent probes based on intramolecular charge transfer（ICT）mechanism.Therefore,triphenylamine derivatives are widely used in the design and synthesis of fluorescent probes.Based on the fluorophore framework of TPA,this paper designed and synthesized three kinds of fluorescent probes with ICT or AIE mechanism through structural modification,and investigated their recognition performance and practical application based on their optical response.The main research contents are as follows:1.Using 4-bromotriphenylamine as the raw material,the probe TPA-CN was synthesized,which can detect CN^-with the naked eye.Based on the ICT process blocking recognition strategy,TPA-CN exhibits a significant fluorescence enhancement toward CN^-in the Me CN/H₂O（5/5,v/v,HEPES 20m M,p H=7.60）system.The probe can specifically recognize in complex environments and detect CN^-sensitively,and the detection limit of 2.99×10^-6M.The probe can be applied to the detection of CN^-in germinated potatoes.2.Based on the recognition strategy that uses an aldehyde group to facilitate the thiolysis of dinitrophenyl ether,the probe TPA-HS was synthesized to detect HS^-.The probe is slightly soluble in THF/H₂O（2/8,v/v,HEPES 20 m M,p H=7.12）mixed solution,and reacts with HS^-to release its precursor 3-1 with AIE properties.TPA-HS can quickly recognize HS^-within20 minutes,and the detection limit is as low as 7.63×10^-6M.In addition,the probe has been successfully used to detect HS^-in real samples.3.The probe TPA-N was synthesized by combining the TPA derivative with the malononitrile group,and the dual function detection of N₂H₄and Cl O^-in aqueous solution was realized.TPA-N has the advantages of high selectivity,strong anti-interference ability and low detection limit(1.61×10^-6M)in response to N₂H₄in the DMF/H₂O（4/6,v/v,PBS 20 m M,p H=9.09）system.In the Me OH/H₂O（4/6,v/v,p H=6.10）system,TPA-N reacts with Cl O^-to release the intermediate compound 2-1 with AIE properties,which has the advantages of high selectivity and sensitivity,strong anti-interference ability and low detection limit(3.40×10^-6M)in response to Cl O^-.In addition,the probe has low cytotoxicity and has been successfully applied to the detection of N₂H₄in actual water samples and the fluorescence imaging of ClO^- in biological cells.