The Synthesis And Application Of Cyanine Dyes

With the rapid development of fluorescence technology,fluorescence detection and fluorescence imaging based on organic fluorescent dyes have been widely used in environmental and biomedical research fields.Among them,cyanine dyes have attracted a lot of attention from scientists because of their large molar extinction coefficient,high fluorescence quantum yield,adjustable absorption and emission wavelengths(from visible to near-infrared region),and many other sites that can be modified.Many commercial cyanine dyes still have problems such as low industrialization yield and high cost of sales,which limits their large-scale application.Therefore,optimizing the synthesis process of cyanine dyes is of great significance for broadening their market and application promotion.This thesis mainly includes the following contents:We have successfully prepared nine kinds of cyanine dyes,and optimized the preparation of cyanine dyes from the reaction conditions,post-treatment and by-product analysis,and discussed the heterocyclic structure,conjugated chain length and water solubility.The influence of three major factors on the photophysical properties of the cyanine dyes showed that the benzofluorene heterocycles caused the cyanine dye to shift red by about 50 nm compared with the anthracene heterocycle.A double bond was added to the conjugated chain,the spectrum was red-shifted is about100 nm.The introduction of a water-soluble group on the side chain has no significant effect on the spectrum of the cyanines.Based on the synthesis of cyanine dyes,two kinds of cyanine dyes with Cy 7 and Sulfo-Cy 7 in the near-infrared region were selected and conjugated with2-amino-2-deoxy-D-glucose(2DG).The two fluorescent probes Cy 7-2DG and Sulfo-Cy 7-2DG were prepared and the active targeting in the cells was studied by the laser confocal microscopy.