Synthesis And Application Of Small Molecule Fluorescent Probes Based On Coumarin And Naphthalene

BackgroundSmall biological molecules play a very important role in life sciences,medicine and environmental.For example,copper ions play an essential role in redox reactions and signal transduction.Pyrophosphate is involved in the hydrolysis of adenosine triphosphate,the polymerization of DNA and RNA,and other processes.As an endogenous gas signal molecule,hydrogen sulfide has important regulation function in the pathological and physiological processes of the cardiovascular system,nervous system,and immune system.Therefore,the identification of copper ions,pyrophosphate and hydrogen sulfide in organisms helps to further understand their roles in the metabolism of the biological systems and make accurate diagnosis of related diseases.ObjectivesDesign and synthesize small-molecule fluorescent probes with high sensitivity and selectivity for the detection of copper ions,pyrophosphate and hydrogen sulfide,to provide a visual detection method for the diagnosis and treatment of related diseases.Methods1.Three fluorescent probes L1,L2-Cu²⁺and L3-Cu²⁺were designed and synthesized and further characterized by ESI-MS,NMR and IR.2.The response of the probes to various metal ions,anions and amino acids were tested by UV-vis absorption and fluorescence spectroscopy.3.The pH-dependent experiments were used to explore the appropriate application environment for the probes.4.Liver normal cells?LO-2?,liver cancer cells?HepG-2?,and lung cancer cells?A549?were cultured.The cytotoxicity test was used to detect the cytotoxicity of the probes.5.Fluorescent cell imaging experiments were performed to test the feasibility of probes applied to the biological environment.Results1.Copper ions fluorescent probe L1,pyrophosphate fluorescent probe L2-Cu²⁺and hydrogen sulfide fluorescent probe L3-Cu²⁺were successfully synthesized,and characterized by ESI-MS,¹H NMR and ¹³C NMR.2.The results of UV-vis absorption and fluorescence spectra showed that:?1?The probe L1 had good sensitivity and selectivity to Cu²⁺ions,and it was not interfered by other metal ions and anions when coexistence.?2?The probe L2-Cu²⁺showed a high sensitivity and selectivity for PPi via fluorescence“turn-on”manner over other anions,including Pi,ATP,ADP and AMP.?3?The probe L3-Cu²⁺could detect H₂S with high selectivity and sensitivity and was not easily interfered by various amino acids.3.The results of cytotoxicity test indicated that the concentration of the probe in the range of 0-10?M had no significant cytotoxicity and side effects on the cells.4.The results of fluorescence cell imaging implied that L1,L2,L2-Cu²⁺,L3 and L3-Cu²⁺all have good cell permeability and can be used for the detection of copper ions,pyrophosphate and hydrogen sulfide inside and outside cells,respectively.Conclusions1.The copper ion fluorescent probe L1,the pyrophosphate fluorescent probe L2-Cu²⁺and the hydrogen sulfide fluorescence probe L3-Cu²⁺were successfully designed and synthesized.2.Three fluorescent probes were successfully applied to the detection of copper ions,pyrophosphate and hydrogen sulfide in the cell environment.