Design And Investigate The Properties Of Fluorescent Chemodosimeters Based On Salicylaldehyde Schiff Base

Fluorescence probes have the advantages of visualization,simple operation,high sensitivity and high selectivity,which make up for the defects of traditional detection methods.In many organic small molecule fluorescent probes,the fluorescent probes based on salicylaldehyde schiff bases have unique advantages such as easy derivation,simple synthesis and high yield,and have become the research hotspot in the field of fluorescent molecular probes.In this paper,two kinds of fluorescent molecular probes based on salicylaldehyde schiff bases were designed and synthesized,their properties were studied in detail,and their practical applications were explored.The main contents are as follows:Firstly,we developed a highly selective enhanced fluorescent probe for the detection of acetaldehyde.Acetaldehyde is one of the most important flavor constituents in liquor and spirits,which is the major origination of its spicy taste.However,as a human carcinogen,excessive intake of acetaldehyde is harmful to health.In this work,a fluorescence sensor of 5-methoxycarbonylsalicylaldehyde hydrazone(29)was developed to achieve a fast and highly selective response for acetaldehyde.Mechanism study showed that when 29 combined with acetaldehyde in aqueous solution at neutral p H,an aggregation-induced emission luminogen(AIEgen)was produced,resulting in a “turn-on” fluorescence response.Compared to gas chromatography,the traditional detective method for acetaldehyde in liquor and spirits,fluorometry using 29 has a number of advantages including simplicity,quick response and capability of real-time detection.More importantly,the detections of acetaldehyde in real liquor and spirits samples were successfully achieved.Secondly,we designed a ratio fluorescent probe 34 for p H detection.p H is an important physiochemical parameter in environmental and biological samples.Monitoring p H is critical to protect our environment.The ratio fluorescent probe can effectively overcome the system error,so the ratio fluorescent probe with two emission channels is the most desirable.34 exhibited different colors of fluorescence by undergoing protonation-deprotonation in acidic and alkaline solutions,respectively.It could be used as a ratio p H probe.More importantly,this probe can also be used as a good endoplasmic reticulum probe,which can be used in Hela cancer cells for specific endoplasmic reticulum localization,inducing endoplasmic reticulum stress and cell apoptosis,and has obvious strong light toxicity to cancer cells in visible light(400-700 nm),while non-toxic to normal cells in the dark.34 has shown a great prospect in the killing of photodynamic cancer cells due to its specific location of endoplasmic reticulum,excellent photostability,and high efficiency in producing reactive oxygen species.