The Design?Synthsis And Imaging Of Fluorescent Probes Based On Detection Of Nitrogen-containing Small Molecules

Due to the fast response time,real-time visualization and noninvasive nature,fluorescent probes are widely applied in chemical analysis,biology,and medicine study.The use of fluorescent molecular imaging technology to study the pathological and physiological functions of intracellular active small molecules?RSMs?has been a hot topic,As their unique physiological roles in life processes,the reactive nitrogen small molecules such as ONOO^-have attracted attention.It is very important that development of fluorescent probes with high selectivity and sensitivity,short response time,small background interference,less organism photodamage in biological detection.In this paper,several novel fluorescent probes were designed and synthesized by using some fluorophore-linked specific recognition groups with excellent properties.Combined with confocal imaging technology,real-time monitor peroxynitrite anions and hydrazine in biological samples.The details are as follows:?1?Peroxynitrite?ONOO^-?is closely related to various physiological and pathological processes.Real-time,selective,and sensitive detection of ONOO^-is of great importance.Develop a fluorescent probe for imaging ONOO^-in biological system,with a benzoindocyanine fluorophore as the scaffold and a diphenylphosphinyl group as a hydroxy protecting group.When the probe CyPP responds with ONOO^-,the hydroxy fluorophore is released,the UV absorption has a large red shift?527-360=167 nm?,and the fluorescence intensity is enhanced by more than 20 times.this probe displays high selective detection of ONOO^-over other various bioactive molecules and could quantitatively and sensitively detect ONOO^-with a low limit of detection?LOD?of 0.38?M by fluorescence method and0.50?M by UV method.The probe CyPP has good water solubility and biocompatibility,and was successfully applied for fluorescence imaging of ONOO^-in living cells??2?Based on the intramolecular charge transfer?ICT?mechanism,a novel near-infrared?NIR?and naked-eye fluorescence probe DCIPP was developed with“turn-on”fluorescence property for monitoring ONOO^-in living cells.The probe DCIPP composed of a dicyanoisophorone electron-accepting scaffold and a reactive electron-drawing diphenyl phosphoryl group for imaging ONOO^-.Upon addition of ONOO^-,the fluorescence intensity of DCIPP enhances obviously at 665 nm in emission spectra,and the colour of DCIPP solution changes from pale yellow to purple at the same time.Based on the nucleophilic propensity of ONOO^-,this probe displays high selective detection of ONOO^-over other various bioactive molecules and could quantitatively and sensitively detect ONOO^-with a low limit of detection?LOD?of 33 nM by fluorescence method and 0.29?M by UV method.Moreover,DCIPP was successfully applied to the fluorescence imaging of ONOO^-in living cells and zebrafish with good cell-membrane permeability and low cytotoxicity.?3?The hydrazine and its aqueous solution are highly toxic to humans and animals,and can strongly erode the skin and have a detrimental effect on the eyes and liver,has been identified as an environmental contaminant and a probable human carcinogen.In this paper,a nucleophilic property of hydrazine was used to construct a N₂H₄ fluorescent probe CCB with a coumarinocoumarin as a fluorophore and a benzoyl group as a recognition group.Hydrazine nucleophilic attack eliminates benzoyl groups and restores fluorescence.With hydrazine attacked CCB,the nucleophilic reaction occurs,and then the benzoyl group is eliminated to release the fluorescent,thus leading to a strong fluorescence enhancement..The probe CCB has the advantages of short detection time?10 min?,low detection limit?14 nm?,and has been successfully applied to cell imaging.