Synthesis and spectra of a kind of novel longer-wavelength benzoxazole indole styryl cyanine dye with a carbazole-bridged chain.

Based on cyanine dye probe oxazole yellow (YO) and Cy(3), a series of novel styryl cyanine dyes were designed and synthesized. Carbazole was inserted into the structures of YO and Cy(3) to act as a bridge to link the benzoxazole and indole group. This modification resulted in a novel kind of benzoxazole indole styryl cyanine dye with a carbazole-bridged chain. The dyes were characterized by (1)HNMR and MS. The spectra of the novel dyes were also performed and the results showed that the maximum emission wavelength of the carbazole styryl cyanine dye was shifted red, the Stokes shift increased and the fluorescence intensity enhanced compared with those of YO and Cy(3). These results indicated that the novel dye could be used as an excellent fluorescent probe in biological labeling.