Design,Synthesis And Application Of Reactive Fluorescent Probes For Reactive Oxygen Species

Among various reactive oxygen species,hydrogen peroxide(H₂O₂)is a relatively common small molecule of reactive oxygen species,which plays a vital role in a wide range of physiological and pathological processes in the body.The misregulation of H₂O₂ in cells can cause a series of organ dysfunctions.Excessive H₂O₂ may cause oxidative damage to nucleic acids and change the structure of proteins,leading to human aging and various diseases,such as neurodegenerative diseases,diabetes,and cancer.As another type of reactive oxygen species,HOCl/Cl O^-has a very important role in the innate immune system.However,when the body's HOCl/Cl O^-secretion disorder occurs,it can also cause a series of diseases,such as cardiovascular disease and osteoarthritis.Traditional analysis methods are difficult to detect real-time reactive oxygen species in living cells,and their sensitivity and selectivity are easily interfered in relatively complex biological environments.Therefore,the development of highly sensitive,highly selective,and visualized small-molecule fluorescent probes to detect intracellular hydrogen peroxide and hypochlorite,so as to further understand the pathological process of diseases closely related to these two reactive oxygen species important.In this work,three small-molecule reactive fluorescent probes were designed and synthesized to detect two reactive oxygen species,hydrogen peroxide and hypochlorite.The probe itself does not emit fluorescence or emits only a small amount of fluorescence.After reacting with active oxygen,the fluorescent group is released,thereby emitting intense fluorescence to achieve the purpose of detection.Subsequently,the probes were studied for spectroscopic properties,density functional analysis,and live cell imaging.The main research contents are as follows:The synthesis methods of three small-molecule fluorescent probes were studied.HRMS,¹HNMR,¹³CNMR and MFS were used to identify the structure of the target probe and study its spectral properties.Subsequently,the probes were studied for anti-interference ability,kinetic response,p H stability and temperature sensitivity.The results showed that all three probes have outstanding specificity and stability,as well as excellent sensitivity,and their detection limits are as low as nanomoles level.Based on this,the density functional analysis and response mechanism of the probe were studied by Gaussian 09,Gaussian View and HPLC.The CCK-8 method was used to determine the toxic effects of the probe on He La cells and A549 cells.In addition,confocal microscopes were used to study the imaging of three probes in living cells.The test results at the cell level showed that the synthesized target probes exhibit low toxicity to cells,and can achieved fluorescence imaging in living cells.At the same time,rhodamine-based fluorescent probes for the detection of hydrogen peroxide have been used for research on mitochondrial targeting in living cells.The results showed that the probe Rh B-NIR and the commercially available mitochondrial targeting dye rhodamine 123 highly overlap the fluorescence distribution in the cells,proving that it has favorable mitochondrial targeting potential.This research provides new ideas and methods for the diagnosis and prevention of related diseases by realizing the detection of reactive oxygen species,which has important theoretical significance and potential application value.