The Synthesis And Applications Of Specific Peroxynitrite Fluorescent Probes

In natural water,peroxynitrite(ONOO~-)can directly degrade several types of dissolved organic matter(DOM)through oxidation and nitrification reaction pathways,therefore,it plays an important role in the process of degrading DOM.In the human body,peroxynitrite is one of the endogenously generated reactive oxygen species(ROS),not only plays a vital role in signal transduction,but also has an antibacterial effect in biological systems.However,peroxynitrite can destroy various molecules in living cells,it has been reported that the abnormal level of peroxynitrite in the body is related to many human diseases,such as cancer.However,due to the nature of peroxynitrite,such as strong oxidizing property,short half life,and high reactivity,the related role in the living system has not been fully elucidated.Therefore,the development of detection methods for the detection of peroxynitrite in environmental and biological systems is very important,not only for better understanding of its biological role,but also for the early diagnosis of related diseases.Among many detection methods,small-molecule fluorescent probes have attracted much attention because of their simple operation,high selectivity,non-invasiveness,and dynamic real-time observation.In the past few years,many fluorescent probes have been developed for the detection of peroxynitrite,but most of the reported peroxynitrite probes show fluorescence changes only at a single wavelength,this makes them affected by many factors,while the ratiometric fluorescent probe can eliminate the influence of these factors,so that the analysis results are more accurate.In addition,many probes exhibit some shortcomings,such as short emission wavelength,long response time,poor selectivity,and low sensitivity,this will limit their application in biological imaging.Therefore,in order to be able to provide valuable tools for detecting peroxynitrite,it is important to develop ratiometric fluorescent probe,or develop fluorescent probes with fast response,high selectivity,high sensitivity,and long emission wavelength.Based on this,three novel peroxynitrite fluorescent probes were designed and synthesized in this paper,and bioimaging was achieved at the cellular level or vivo level.A red-emitting long wavelength fluorescent probe Red-PN was developed for peroxynitrite detection and imaging,which contains a rhodamine derivative fluorophore and hydrazide reactive group.Compared with other ROS/RNS,the probe shows high sensitivity and specificity for peroxynitrite,and the probe solution has obvious color change before and after reaction(from colorless to pink),so the probe can be applied for the naked-eye detection of peroxynitrite.In addition,the probe has low toxicity to cells and has been successfully used to detect exogenous and endogenous peroxynitrite in RAW 264.7 cells and zebrafish.A ratiometric peroxynitrite fluorescent probe CPD-ratio was synthesized based on the coumarin-pyridine derivative fluorophore and borate recognition group.The emission peak of the probe itself is at 565 nm,when the probe reacts with peroxynitrite,the benzyl protecting group will be cleaved from the probe,releasing the fluorophore,so that the emission peak blue shifts to 500 nm,achieving the ratiometric detection.CPD-ratio has the advantages of fast response(<30 s),high selectivity and sensitivity.Finally,it has been effectively used for the ratiometric imaging of endogenous and exogenous peroxynitrite in RAW 264.7 cells.A new fluorescent probe BC-PN was synthesized using bis-coumarin fluorophore BC-dye and borate as specific recognition groups.The probe BC-PN has many excellent properties.For example,it can specifically detect peroxynitrite compared with other species,it has excellent sensitivity(detection limit of 4 nM),and can quickly respond to peroxynitrite.Using this simple fluorescent probe,we achieved the detection of endogenous and exogenous peroxynitrite in living cells and zebrafish.In addition,BC-PN has effectively differentiated cancer cells from normal cells by imaging different levels of basal peroxynitrite.In summary,the three novel peroxynitrite fluorescent probes synthesized in this paper,which can detect peroxynitrite sensitively,specifically,and quickly,and can all realize the detection application in biological samples.