Design And Properties Of Novel Fluorescent Molecular Probes For Detection Of Fluoride And Amyloid-like Proteins

Cations, anions, amino acids, small neutral molecules and protein play significant roles in chemical and biological processes. Therefore, qualitative and quantitative monitoring of their distribution in living systems could be crucial to give more insight into their biological function, as well as into their related disease.Fluorescent sensors have been developed to be a useful tool to sense in vitro and in vivo above-mentioned biologically important species. The recognition process, using host-guest interactions or chemical reactions between analyte and probe, will invoke a change of the fluorescence signal in the form of quenching, enhancement or wavelength shift due to either electron transfer, charge transfer or energy transfer processes. Because of their specificity and sensitivity monitoring with fast response time, the design, synthesis, and application of fluorescent sensors have attracted increasing attention and become a very active research field.This thesis contains six chapters:Chapter 1:A brief survey of design principles, recent progress and improvements in the development of small-molecular fluorescent probes is presented.Chapter 2:An innovative reaction-based boron-dipyrromethene dye (BODIPY) is designed and proved to be a highly selective, sensitive, and fast chromogenic fluorescent chemodosimeter for fluoride. Computational studies are in agreement with the experimental results.Chapter 3:A new series of efficient styryl-substituted BODIPY dyes for reaction-based sensing of fluoride ions reported and their structure-optical property relationship has been evaluated. They can be utilized as visible probes owing to the clear color change upon addition of fluoride ions and one of the red-emitting probes exhibits the largest blue-shift ever observed of the fluorescence band when subjected to fluoride ions (117 nm).Chapter 4:A highly selective ratiometric red-emitting probe incorporating both 2,4-dinitrobenzenesulfonyl and trihexylsilylacetylene group shows fast and high differential responses for fluoride and hydrogen sulfide sensing. Moreover, the probe has been used successfully for bioimaging the hydrogen sulfide in living cells.Chapter 5:A new series of fluorescent amyloid-binding probes containing an amino naphthaleny-2-cyano-acrylate (ANCA) motif has been synthesized and evaluated for its capability to fluorescently discriminate between different types of amyloid deposits. The imaging studies of staining amyloid deposits in brain tissue are also presented.Chapter 6:A novel class of near-infrared molecules based on the donor-acceptor architecture has been synthesized and evaluated as amyloid deposits imaging probes. Computational studies could reproduce the experimental trends well.