Synthesis And Application Of Fluorescent Probes For Some Gas Molecules

Fluorescent probes are chemical systems that convert effective chemical stimuli into readily observable spectral information.Compared to the traditional ways of detecting ions,molecules and biological macromolecules,fluorescent probe has the advantages of high sensitivity,low cost,strong visualization and small damage in living organisms,it has been widely used in medicine,counter-terrorism,environmental monitoring and other fields.In environmental and biological systems,there is an increasing demand for detection and monitoring of gas sensors.Applications of such sensors include real-time control of clinical diagnostic gases,toxic gases and environmental contaminants.In this paper,several fluorescent probe molecules were designed and synthesized by BODIPY and Quinoline fluorophore,which are used for qualitative and quantitative detection of nitric oxide(NO),a signal gas molecule related to physiological and pathological processes,phosgene,a poisonous gas causing pulmonary edema,and hydrogen cyanide gas(HCN),a blood poison with low lethal dose and high toxicity.The specific content are as follows:1.We designed and synthesized a fluorescent probe RBA with 3-substituted BODIPY as chromophore and secondary amine as NO activity site.RBA can quickly detect NO within 10 seconds and generate the product of N-nitrosamines species(RBA-NO,?f=0.87,by using cresol purple in CH3OH as standard)in aerobic solution,the photoinduced electron transfer from secondary amines to the core of BODIPY was blocked,which led to the activation of fluorescence.The sensing reaction was also high sensitivity(LOD=10 nM).The selectivity of the probe to NO was higher than that of other related analytes,except the interference of some reduction reagents,due to the significant interference effect caused by the competitive reaction between these reducing substances and NO.In addition,we detected endo-exogenous NO in living cells and zebrafish,and significant fluorescence reduction was demonstrated that the effects of glutathione through cell imaging experiments.These results suggest that the response strength of RBA to instantaneous NO depends on the level of GSH in living cells.2.We have developed an efficient method for the ?-chlorination of 2-methylpyridine compounds by the rapid(10 min)reaction of triphosgene/triethylamine with 2-methylpyridine N-oxide(18 substrates)at room temperature.This reaction has been demonstrated to be a Boekelheide reaction mechanism via reversible hetero-claisen rearrangement.One of the substrates 2g has been used as a high selectivity fluorescent probe for phosgene sensing with a rapid response(10 s)and high sensitivity(LOD=3.4 nM).Finally,we prepared a test strip loaded with probe to quickly and selectively monitor phosgene.Therefore,the Boekelheide reaction will be used effectively for the synthesis of 2-chloromethylpyridine derivatives and the design of new fluorescent probes for phosgene.3.We have designed and synthesized compounds BBQA,HBQA and PPQA with 6-position N-alkyl and benzene-substituted aminoquinoline and dicyanovinyl group as cyanide reaction sites,which are as novel cyanide probes based on intramolecular charge transfer(ICT)process.All of them can respond to cyanide with high efficiency and sensitivity in three modes of ratiometric,turn-off and turn-on,respectively.The results showed that BBQA(LOD=34.9 nM,25 min)stood out by comparing the properties of the three probes in the reaction with cyanide,which could be used for further study of the reaction and photoluminescence mechanism.Finally,we made BBQA into test paper,and detected hydrogen cyanide gas in the concentration range of 0-43 ppm in the air atmosphere.