Synthesis, Characterization And Application Of The Water-Soluble Conjugated Polymer With Azobenzene Side Chains

In recent years, a lot of water soluble conjugated polymers have been synthesized and used in the world. Water soluble conjugated polymers(WSCPs) in the structure mainly consists of two parts :(I)πconjugated backbone, decide the photophysical properties of conjugated polymers, such as absorption and emission spectra, light capture capacity and quantum yield.(II) side chain hydrophilic groups, such as cationic quaternary ammonium salt, anionic carboxylate, sulfonate, as well as hydrophilic groups. Based on the background of this study and combined with the development of cell detection in hypoxia environment, we designed and synthesized two kinds of water soluble conjugated polymer: PF4(containing polyethylene glycol water soluble side chain) and PF6(containing quaternary ammonium salt cationic water soluble side chain). Polyfluorene has blue fluorescence, via atom transfer radical polymerization(ATRP) mode, azobenzene connectes to the main chain(azobenzene is a hypoxia sensitive group and the fluorescence quenching agent, under the hypoxia condition, interrupted by azo reductase, then lose the fluorescence quenching ability, fluorescence of the material recovery). By means of nuclear magnetic resonance spectroscopy(NMR 1H), UV absorption(Spectra UV) and fluorescence emission(Spectra Fluorescence) characterization, it was proved that the compounds were successfully synthesized. We studied the basic photophysical properties of material, optical stability, self assembling behavior, fluorescence quenching mechanism, in the presence of reductase fluorescent material recovery and hypoxia environment material for cell imaging effect of inquiry. The experimental data show that we designed and synthesized a water-soluble conjugated polymer probe material with low cytotoxicity(MTT method) and can have a good imaging effect on the cells under hypoxia environment.