Synthesis Of Polymethine Cyanine And Complex Merocyanine Dyes, Spectral Properties As Well As Their Application

Cyanine dyes have been studied for many years and widely used in optical materials. With the development of technology, cyanine dyes exhibit more extensive utilities, especially in biomedical area. There are many literatures on their applications in these areas. In this paper, the application of cyanine dyes in determination of amino acid, protein investigation, tumor detection, cancer cells identification, macromolecular tag, photodynamic therapy (PDT) are presented, and the synthesis of cyanine dyes in recent years are introduced.Six kinds of nitrogen heterocyclic intermediates were synthesized. Then,7 different cyanine dyes were synthesized by using these intermediates and 1H-indole-3-carbaldehyde as starting materials. The products were identified by 1H NMR, IR, MS and UV-vis spectra.The UV-vis spectra and fluorescence of 7 kinds of cyanine dyes in various solvents are investigated. The results indicated that the absorption band shapes do not change in those solvents, so do the absorbance. Theλmax of cyanine dyes have hypochromatic shifts with increase of permittivity in protic solvents, but the stokes shifts of them have opposite trends. Similarly, theλmax of cyanine dyes have bathochromic shifts with increase of refractive index in aprotic solvent, but the stokes shifts of them have opposite trend The fluorescence intensity and stokes shifts of 7 cyanine dyes had disparity in different solvents.The UV-vis and fluorescence spectroscopy under physiological conditions of free dyes and in the presence of DNA or BSA were investigated. The results reviewed that the spectroscopy of three kinds of water-soluble dimethine cyanine dyes was same almostly both in the presence of DNA/BSA and free. Theλmax of both the monmethine cyanine dyes and the complex merocyanine dyes have bathochromic shifts of 4-6 rm when they were in the presence of DNA, and significant enhancement of the fluorescence intensity for dyes was observed (7-80 times). They could be proposed as fluorescent probes for DNA detection. The spectroscopy of UV-vis monmethine cyanine dyes and complex merocyanine dyes was almost the same both in the presence of BSA and free.The two kinds of monmethine cyanine dyes were studied in staining living cells. One of them have good staining result for leukemia cells. The complex merocyanine dyes were applied in PDT. The results showed that they have growth inhibition for K562 (leukemia cell) and can be regarded as potential candidates as sensitizers for PDT.