Spectral and kinetic characteristics of indotricarbocyanine complexation with albumin

Complex formation of albumin with tricarbocyanine dyes containing phosphonate groups

“…Interestingly tricarbocyanine dyes with five hydrophilic groups (four sulfonate and one carboxylic) have K b almost by two orders of magnitude lower than ICG with two sulfonate groups and cypate with two carboxylic groups. 27 It should be pointed out that the values of K b for dyes 1-3 were obtained in this study and 7 under the same conditions from the increase in the absorption or fluorescence of a dye upon the addition of albumin. Our value for dye 1 is smaller by a factor of five than that given in ref.…”

“…Complex formation between a dye and protein or nucleic acids increases the dye fluorescence and stabilizes the dye in the complex, which is the basis of their practical use. [3][4][5][6][7] Cyanine dyes have found a wide application as fluorescent probes for diagnosis in medical research. The absorption and fluorescence spectra of these dyes with a long polymethine chain are in the NIR range that provides the optimal depth of light penetration in tissues and stipulates the use of these dyes for investigations of biological structures and in cardiological medical studies of blood vessels.…”

“…This enhances the fluorescence efficiency of the molecular dye non-covalently bound to a protein. 7,15 The dye efficiency in the fluorescence methods is determined by contributions of intersystem crossing, internal conversion, photoisomerization, and fluorescence. The latter increases upon complex formation.…”