Development Of Fluorescent Probes Based On The Phenanthrimidazole Structure And Their Analytical Applications

Phenanthrimidazole compounds based on excited-state intramolecular proton transfer（ESIPT）mechanism are widely used in organic light emitting diodes（OLEDs）,metal organic frameworks（MOFs）and fluorescence sensing fields.The preparation method of supramolecular polymer based on quadruple hydrogen bond is simple and easy to realize the integration of multiple functions.2-urea-4[1H]-pyrimidine ketone（UPy）is one of the quadruple hydrogen bond construction units commonly used in supramolecular polymers.It is often used to modify the fluorescent mother nucleus to construct quadruple hydrogen bond polymers.Modifying the parent nucleus of phenanthrimidazole compounds with UPy to construct quadruple hydrogen bonded polymers and explore their properties will help to further expand the application of phenanthrimidazole compounds.Superoxide anion radical(O₂^·-)and hypochlorous acid（HCl O）are two important reactive oxygen species（ROS）.O₂^·-is the first reactive oxygen species produced in human body,which will further produce hydrogen peroxide（H₂O₂）under the action of superoxide dismutase（SOD）;H₂O₂ and chloride ion（Cl^-）can produce HCl O under the catalysis of myeloperoxidase（MPO）secreted by cells.A large number of studies have shown that the abnormal expression of HCl O and O₂^·-can lead to many diseases,such as inflammation,neurodegenerative diseases,autoimmune diseases,and even cancer.Therefore,the study of the production,distribution and concentration changes of HCl O and O₂^·-in cells and in vivo is of great significance for the diagnosis,treatment and pathogenesis of related diseases.In this paper,a fluorescent probe based on phenanthrimidazole structure was designed and synthesized,and its properties in the imaging detection of reactive oxygen species such as HCl O and O₂^·-were explored.Based on UPy,quadruple hydrogen bond polymers were preliminarily synthesized,and the synthesis conditions were screened.The specific work is as follows:（1）Lysosomal localization fluorescent probe G-Lyso was synthesized based on the structure of phenanthrimidazole.The probe showed good selectivity for HCl O,and exhibited rapid response and high sensitivity.The probe was used to evaluate HCl O level in cardiomyocytes treated with anticancer drugs.It was found that there was almost no increase of HCl O level in cardiomyocytes when treated with cyclophosphamide and imatinib mesylate.It was observed that myocardial cells treated with camptothecin,cisplatin,gefitinib,5-fluorouracil,paclitaxel and erlotinib showed moderate increase in HCl O level.The HCl O level in cardiomyocytes treated with adriamycin increased most significantly.The above results showed that different anticancer drugs can lead to different degrees of lysosomal oxidative stress in cardiomyocytes.The probe shows a certain application potential in the screening of anticancer drugs.（2）Using phenanthrimidazole derivatives as fluorophores,two fluorescent probes that can specifically detect HCl O and O₂^·-in different fluorescent channels were synthesized.It was found that phorbol ester（PMA）can lead to the simultaneous increase of HCl O and O₂^·-in cells.Polymer nanoparticles were obtained by UPy mediated supramolecular polymerization of quadruple hydrogen bonds,and the synthesis conditions were preliminarily selected.