Abstract:

In order to investigate the application of fluorescent dyes in the field of bioanalytical technology,the absorption and emission spectra of four water-soluble squarylium indocyanine dyes in such surfactants as cetyltrimethy-lammonium bromide（CTAB）,sodium dodecyl sulfate（SDS） and Triton X-100（TX-100） in micelle-mimic physio-logical conditions were measured.The results show that there exist effective interactions between the dyes and the micelles in an order of CTAB〉TX-100〉SDS,that the maximum absorption and emission wavelengths of the dyes all exhibit a red shift due to the formation of micelles in surfactant solutions, that the maximum absorption wavelength exhibits a red shift of 11 - 16nm, that, with the increase of CTAB concentration which is less than the critical micelle concentration, dyes a and d form H-aggregate whereas dyes e and f form not only H-aggregate but also J-aggregate, that the aggregates disaggregates when CTAB concentration is larger than the critical micelle concentration, and that the fluorescent densities and quantum yields of the dyes significantly improve in appropriate surfactant solutions.

Key words: squarylium cyanine, dye, surfactant, spectral property, water solubility