Abstract: | The results of fluorescence quenching measurements, obtained for a dye-substituted aqueous gelatin solution during the sol-gel transition, are presented. Simultaneous optical polarization rotation and fluorescence studies allow us to find the dependence of the fluorescence yield on the amount of helix created in the medium. The exact gel point has been found as the point of inflection on the fluorescence yield versus the helix amount plot. The second-order character of the sol-gel transition is shown, which is in agreement with the theoretical predictions obtained by use of the percolation theory. |