Synthesis And Spectral Properties Study Of Cy5 Dyes

With the development of life science, there is a growing requirement for high sensitive detection technologies in analysis. Fluorescence label is a convenient method. Cyanine dyes have been widely used as fluorescence probes for biosystem in biomolecular analysis field to their large molar extinction coefficient, broad absorption spectra and wavelength tenability.The second part of article, two novel new cyanine dyes were designed and synthesized which contain three ammoniums and the ultimate yield was 25%. The novel cyanine dyes were characterized by ~1H NMR and TOF-MS. The spectrums in different solvent were tested. The result indicates that the new dyes have higher fluorescence quantum yields in water. In methanol, they were found to exhibit a large Stokes shift. In the protic solvent, the violet absorption of that novel dyes would emerge blue shift as the increase of polarity; in the aprotic solvent, the violet absorption of that novel dyes would emerge red shift as the increase of polarity.In this paper of the third chapter, Six novel Cy5 dyes were designed and synthesized, which can have both stabilization and water-solubility. More longer and more flexible alkyl chains ended with hydroxyl group and ester were linked to N-atom in Cy5 chain. Photofading behaviors of the dyes were investigated through determining the change of the maximal absorbance of the dyes. The results show that the dyes with flexible alkyl chains more short more stabilization, and. the hydroxyl group improved photostability compared with only alkyl chains.