The Development of Novel Cyanine Dyes with Vinylsulfone Group for the Optical Imaging

Abstract

In this thesis, novel vinylsulfone (VS) cyanine dyes (em. 550−850 nm) were designed and synthesized for fluorescent labeling of biomolecules via 1,2-addition reaction in aqueous conditions. Due to the virtue of chemical structures of both fluorophore and reactive group, these dyes could be significantly stable and reactive in various aqueous/organic conditions. A wide variety of pH, temperature, buffer concentration, and protein were tested for the optimal labeling condition. Also, novel cyanine dyes with a VS group were designed and synthesized for pH indication of biomolecules. Among the series of pH indicator candidates, a selected reactive dye and its labeled biomolecules showed a dramatic change of fluorescence intensity in a wide range of pH conditions. The pH indicating dye can be used to label protein molecules and maintains its optical properties when conjugated to a macromolecule, making it possible to observe pH distributions and changes in acidic and neutral pH conditions. Finally, as an application study using the VS cyanine dyes, we developed a wide ranged fluorescent molecular weight size marker (MWSM). These MWSMs covers upto near-infrared wavelengths, consisted of sequentially arranged VS cyanine dyes enabling proteomic analysis without post-stain for size indication.