Design,Synthesis And The Recongnizition Property Of Novel Cyanine Fluorescent Probes

Iron ions are widely distributed in human cells and are usually contained in tissues and organs.Iron is an important component of hemoglobin,which can promote the transportation of blood in the human body.Its ability to bind with oxygen is essential for participating in oxidation reactions and enzymatic reactions.Deficiency of iron can cause many health problems in the body,such as anemia,loss of appetite,frequent fatigue,reduced work routines and decreased immunity.Excessive accumulation of iron in the blood can lead to a variety of biological diseases,such as fibrosis,tissue damage to different organs and the production of reactive oxygen species,leading to the degradation of proteins,nucleic acids and lipids.Mercury is one of the most toxic pollutants and is widely distributed in various environments.It can exist in different forms,such as metal oxides,ionic forms,metal forms and organic complexes.Among them,mercury ion is the most stable form,it can accumulate through the food chain and eventually enter the human body,resulting in liver and kidney dysfunction,immune system imbalance and even death.Sulfur dioxide is an inevitable product of the combustion of coal and fossil fuels and automobile exhaust,which poses a serious threat to the ecological environment and human health.Generally,sulfur dioxide is inhaled into the human body through the respiratory tract and exists in the form of bisulfite ions in the physiological system.Living in such an environment for a long time may cause respiratory infections and even lung cancer,cardiovascular disease and nervous system diseases.Therefore,there is an urgent need to develop highly selective and sensitive methods to detect Fe³⁺,Hg²⁺and HSO₃^-ions distributed in the environment and biological systems.As a fluorescent dye,cyanine has the advantages of high fluorescence quantum yield,good optical and chemical stability,excitation and emission wavelengths in the near-infrared region,high molar extinction coefficient,and small influence on p H.It is a fluorescent dye that modern scholars choose more.In this thesis,cyanine-based compounds M1,M2,M3 and M4 were designed and synthesized.Fluorescence test experiments show that M1 can recognize Fe³⁺well,and is not affected by other common metal ions.It has a high selectivity.The detection limit for Fe³⁺is0.5μM,it has high sensitivity,and it does not change p H.Sensitive,can effectively identify Fe³⁺in a wide range.M₂ can recognize Hg²⁺well,and is not affected by other common metal ions.It has high selectivity.The detection limit for Hg²⁺is 0.6μM,it has high sensitivity,and it is not sensitive to p H changes.Hg²⁺is effectively recognized over a wide range.M4 is a novel compound probe that responds to trace amounts of bisulfite ions.In short,a series of new cyanine near-infrared fluorescent probes have been designed and successfully synthesized,and experiments such as fluorescence tests have been performed.The results show that they can be used to effectively identify Fe³⁺,Hg²⁺,and HSO₃^-,respectively.The detection of heavy metals,environmental monitoring and disease prevention and control all have certain significance.