Synthesis Of PH Fluorescent Probes Based On ICT Effect And Its Studies In Cell Imaging

Chapter 1,this part reviewed that the role of intracellular p H?p Hi?in cell structure and function,methods for measuring p Hi in current,classification of fluorescent probes,classical structureof organic small molecule fluorescent probes and its luminescence mechanism with research progress.The significance and implement means of the topic of this paper was introduced briefly in this part.Chapter 2,intracellular p H?p Hi?,especially cytoplasmic p H?⁷.2?in cell,is a crucial parameter in cell function and metabolism.We have facilely synthesized a ratiometric fluorescent probe 6-?2-?benzothiazol-2-yl?vinyl?naphthalen-2-ol?BTNO?via the carbon-carbon double bond bridging of 6-hydroxy-2-naphthyl and 2-benzothiazolyl for quantitative monitoring of fluctuations within cytoplasmic p H in living cells.The F_456nm/F_526nm of BTNO exhibited good linear relation with p H within 7.00-9.50,with a p Ka value of 7.91 ± 0.03,which could be used to detect cytoplasmic p H.Meanwhile,the interferences from probe to physiological function would were reduced via high quantum yield of BTNO,and high quantum yield enhance measurement sensitivity.The p H imaging of BTNO in live He La cells indicates that BTNO can be used to monitor p H fluctuations in living cells.Chapter 3,pH fluorescent probe 4-?2-?6-hydroxynaphthyl-2-yl?vinyl?-1-methylpyridine iodide based on ICT effect and molecular structure tautomerization was synthesized in one step by Knoevenagel condensation reaction.The classic "D-A" structure is obtained via the phenolic hydroxyl group on the naphthalene with the positively charged N atom on the methylpyridine under neutral or acidic conditions,and strong fluorescence was obversed at 586 nm.There is large stokes shift of 196 nm the probe,accordingly,it can avoid interference from excitation light and significantly improve the sensitivity of fluorescence detection.Moreover,p Ka?8.85 ± 0.04?and linear range?7.60-10.00?of the probe are appropriate for mitochondrial alkaline p H imaging.The probe also shows that excellent anti-interference ability,reversibility,light stability and low cytotoxicity.Application of probe in live Hep G2 cells is obtained successfully,indicating that the probe has excellently mitochondrial targeting ability and is used to visualize mitochondrial p H fluctuations in live cells.Chapter 4,A fluorescent probe 2-?2-?6-hydroxynaphthalen-2-yl?vinyl?-3-?6-?triphenylphosphonio?hexyl?benzothiazol-3-ium bromide?HTBT2?with two charges and mitochondrial targeting was successfully synthesized via a facilely method.Fluorescence intensity of HTBT2 at 612 nm emerged distinct p H-dependent behavior in linear range 7.20-8.70 and it's p Ka of 8.04 ± 0.02,which HTBT2 own high sensitivity in measure mitochondrial p H(p H_mito).Moreover,HTBT2 occupies remarkable large Stokes shift of 176 nm which can reduce the interference from exciting light.The mitochondria in SMMC-7721 cells were successfully stained via HTBT2 revealed that HTBT2 hold excellently mitochondrial targeting ability and visual mitochondrial p H fluctuations in live cells was successful achieved.Meanwhile,the differences of p H_mito between normal and cancer cells were observed via HTBT2 indicated that HTBT2 possess potential values as an aidto diagnose diseases associated with mitochondrial p H abnormalities.