ABSTRACT
The binding of organic dyes, including textile dyes, in aquatic media is of current interest in terms of the potential for pollution of natural waters near manufacturing sites. In the presence of the negatively charged biopolymer, homopolymer of L-glutamic acid, bound styryl-7 (S7) exhibited induced optical activity as revealed in circular dichroism spectra. This induced optical activity is a very sensitive monitor of charge and conformation for the electrolyte biopolymer. The chapter presents the results of deployment of S7 as a probe of polymer microenvironment for these polymers in which spectrometric techniques including absorption, fluorescence emission, and circular dichroism were utilized. A commercial sample of humic acid (HA) was subjected to dialysis for removal of low molecular weight components and examined briefly to determine effects of S7 binding. The binding effects on the photophysical properties of S7 are demonstrated for a sample of HA for which some indication of dye aggregation and entrapment in hydrophobic microdomains is in evidence.
