| The function of cells cannot be achieved without the participation of active species and is affected by the cellular microenvironment.As a most important reactive oxygen species（ROS）and a key indicator of biological microenvironments,peroxynitrite（ONOO-）and viscosity are closely related with various physiological and pathological processes by regulating synergistically oxidative stress-related signal transduction.Thus,it is of great importance to develop effective fluorescent probes for detecting or imaging ONOO-and viscosity in cells or in vivo.In this thesis,we took viscosity and ONOO-as the research objects,designed and synthesized a series of probes to detect ONOO-and viscosity.The main research contents are as follows:1.Based on the molecular rotor strategy,a series of near-infrared fluorescence probes based on dicyanoisoflurone dye for viscosity were designed and synthesized.Among them,DCO-V displayed 180-fold fluorescence enhancement when the glycerol content was increased from 0 to95%and insensitivity to polarity changes and p H variations.DCO-V has lower cytotoxicity,and can detect viscosity without interference from other bioactive molecules,such as amino acids,metal ions,oxidizing species and reductive species.Taking advantage of its remarkable properties,DCO-V successfully detected viscosity changes in nystatin-treated Hep G2 cells and zebrafish.More importantly,DCO-V was useful for monitoring the viscosity changes in PC12cells treated with H2O2or glutamate,which are cellular models of Parkinson’s disease（PD）.We expect that this versatile probe can be a promising imaging tool for use in Parkinson’s disease pathology-related fields.2.Based on the merocyanine dye,we constructed a fluorescent probe MC-V-P with typical push-pull electronic effects to detect the viscosity and ONOO-simultaneously.In a nonviscous or low-viscosity environment,the donor group rotates freely around the C-C bond,resulting in nonradiative quenching of the excited state of the probe.As the viscosity of the solution increases,the rotation is restricted,thereby“turning on”the red fluorescence.In addition,by the reaction of MC-V-P with ONOO-,arylboronate is changed to a phenolic group,followed by 1,4-elimination reaction,which resulting green fluorescence.MC-V-P could simultaneously monitor changes of viscosity and ONOO-levels using two resolvable spectral variations.With the advantages of its stability,selectivity and lower cytotoxicity,MC-V-P was successfully employed for imaging viscosity and ONOO-in cells. |
