Design, Synthesis, And Spectroscopic Properties Of BODIPY-based Fluorescent Probes For Biological Signal Moleculars

Biological signal molecules are the messengers of cell communication, which play an important role in the formation of embryo, differentiation, the happening of the tissues and organs, individual growth, development, maturity and aging. The change of biological signal molecules' content is closely related to human health and the detection for biological signal molecules has become a research hotspot in recent years. Due to simple equipment, easy operation, fast analysis speed and high sensitivity, fluorescence techniques have been considered as the ideal methods for the visual assays of biological signal molecules and received extensive attention of research workers. Among many fluorophores, boron-dipyrromethene(BODIPY) fluorescent dyes are widely used in biological markers and fluorescent probes, because of their outstanding characteristics, such as high molar absorption coefficient, intense fluorescence quantum yield, valuable photo- and chemo- stability and exceptional insensititivity to the polarity of solvents as well as to pH. In this thesis, I designed and synthesized probe 1 and probe 2 based on BODIPY and the two fluorescent probes respectively detected biological signal molecule NO or biological thiol molecules.In the second chapter, we designed and synthesized a o-phenylenediamino-based dual-responsive turn-on fluorescent probe 1 for nitrite and NO. Nitrite under acid condition can produce NO, so in the phosphate buffer system(pH = 1 containing 0.5% DMSO), the response of probe 1 with nitrite was tested first. The probe 1 can rapidly and selectively detecte nitrite and the detection limit was 15 nM. Then, we tested the equivalent curve of probe 1 to the NO. the linear range was from 0 ?M to 50 ?M and the probe had good selectivity to NO. Considering benzotriazole being a good leaving group, before NO cell fluorescence imaging, we assessed the response of product BZT to biological thiol small molecules. In the end, the probe 1 imaged nitric oxide well with the aid of the thiol molecules in the cells.In the third chapter, we designed and synthesized dual-emission-channel fluorescent probe 2 for biological thiol(Cys, Hcy, GSH). When the probe 2 meet Cys, firstly, sulfydryl attack the carbon at 8-position generating dynamic controlled product and then amino cyclized to give a thermodynamic control product with the release of blue-green fluorescence. When the probe 2 meet Hcy, due to the spatial steric hindrance of the methyl groups at 1- and 7-position in BODIPY skeleton, amino didn,t proceed amino cyclization to make Hcy as same as GSH to release yellow fluorescence. Therefore, probe 2 could detect cysteine from homocysteine with different chrominance.