Synthesis,Recognition And Application Of Near-Infrared Fluorescent Probes Based On 4-Diethylaminosalicylaldehyde

In this paper,4-diethylaminosalicylic aldehyde?DAS?is used as the fluorogen,and a strong electron-withdrawing group?tricyanofuran?is introduced to DAS by conjugate in order to construct the D-?-A structure.The intramolecular charge transfer?ICT?effect is used to increase emission wavelength of molecule and stokes shift.The specific recognition can be performed by introducing reaction groups.The recognition performance and application of four fluorescent probes were evaluated.1.A new fluorescent probe L1 was synthesized.Probe L1 can recognize H₂S in DMF/PBS?v/v=3/7?,and has better selectivity and anti-interference ability.Probe L1 can detect H₂S in red wine,real water samples,living cells,and gaseous H₂S.It has a wide range of applications.2.A dual-recognition fluorescent probe L2 capable of simultaneously detecting H₂S and HSO₃^-in EtOH/HEPES?v/v=2/8?was synthesized,and the recognition mechanism of the two ions was clarified.L2 can image H₂S in cells and detect H₂S gas,and probe L2 can detect H₂S and HSO₃^-in food.3.A near-infrared emitting fluorescent probe L3 was synthesized,which can recognize Pd²⁺in MeCN/HEPES?v/v=2/8?.The color of L3 solution changes from blue-violet to blue after the addition of Pd²⁺.Probe L3possesses good selectivity and anti-interference ability,wide pH range?2-9?,and can detect Pd²⁺in living cells and real water samples.4.A fluorescent probe L4 for the detection of Hg²⁺in MeCN/HEPES?v/v=2/8?was synthesized.The probe possesses simple synthetic process,near-infrared emission,strong anti-interference ability,wide pH range?6-10?.Upon addition of Hg²⁺,the solution color of L4 changes from purple to blue,and L4 emits red fluorescence.Hg²⁺was detected in actual water samples.