Design And Synthesis Of Fluorescent Probe And Their Application In Water And Polarity Detection

The fluorescent probe has the advantages of easy synthesis,cost-effectiveness,and accurate recognition.Creating new fluorescence sensing strategies and designing new fluorescent probes has always been a hot research topics in the field of fluorescent sensor analysis.In this dissertation,we designed and synthesised three new types of fluorescent probes focused on the needs of detecting trace amounts of water in foods and the polarity change in the organism,and studied in the spectral characteristics of the probes and the identification and transmission of targets sensory characteristics and recognition mechanism,and explored the application feasibility of the designed probe through the analysis of actual samples.The obtained results provide a methodological reference and basis for the design and construction of new types of fluorescent probes and the monitoring of trace water and the polarity of biological organisms.The specific research contents are as follows:1.A fluorescent probe,TTz 1,was synthesized by utilizing a thiazolo thiazole as the parent.The nitrogen atom in the thiazole group of the TTz 1 molecule could form a hydrogen bonding network with the water molecule,resulting in an anti-solvation effect,thereby causing the TTz 1 to exhibit strong fluorescence in water.Based on this effect,we constructed a novel dual-mode sensing system for trace water fluorescenceelectrochemistry,and realized the rapid detection of trace water in organic solvents.The fluorescence intensity in 1,4-dioxane showed a linear relationship with water content at 2%-20%,and the detection limit was 0.019%,and p H,metal ions,amino acids and other reactive substances did not interfere with the detection of water.The method was successfully applied to fluorescence and electrochemical dual-mode the detection of trace water in honey and non-alcoholic organic solvents.In addition,we confirmed the formation of hydrogen bonding network by various analytical methods such as nuclear magnetic resonance.In this study,it is the first time to find the hydrogen bond-induced fluorescence of TTz derivatives,which provides an important reference and basis for the design and construction of novel TTz derivative probes.2.A novel fluorescent probe,Q-2,was synthesized by utilizing fluorene core as a fluorophore.The typical D-?-A structure in the probe showed a obvious solvatochromism effect in solvents,and the fluorescence intensity decreased with the increase of water content.Based on this effect,we constructed a novel fluorescence sensing system for trace water,which could detect trace water in organic solvents quickly and sensitively,and the detection limit of water content was as low as 0.13%.Combined with the test strip manufacturing technology,the probe could also be made as a combination of test strips and smart phones for rapid detection of trace amounts of water.The experiment was based on time-dependent density functional theory(TD-DFT)to theoretically study the luminescence mechanism of the probe,and applied it to the detection of test strips of trace water in honey and alcohol.This method provides new ideas for designing more new fluorescent probes based on the combination of test strips and mobile phone quick detection.3.A new fluorescent probe,L-3,was synthesized by utilizing coumarin aldehyde as the precursor and reacting it with sodium p-toluenesulfinate.Due to the intramolecular charge transfer(ICT)effect,the probe was highly sensitive to polarity,while the twisted intramolecular charge transfer(TICT)effect made L-3 exhibit strong fluorescence emission in high viscosity solvent.Based on this effect,we constructed a new fluorescence sensing system with dual sensing of polarity and viscosity.L-3 was dual emission fluorescence characteristics in both low polarity and high viscosity,and the orientation polarization value in different solvents was a good linear relationship with the maximum emission wavelength value,R2 = 0.9563,which was not responsive to various metal ions and amino acids in the organism.it has been successfully used as a dual-sensor probe of polar and viscosity for imaging studies to distinguish normal cells from cancer cells,which provides a new method for further clinical application.