Controlling J aggregation in fluorescein by bile salt hydrogels

Aggregation of the well-known xanthene dye, fluorescein has been studied in the restricted environment of a bile salt hydrogel and in the bile salt micelles. It has been observed that the hydrogel can be used to some extent “control” the type of aggregation in fluorescein, since J-aggregate formation is favored at the expense of H-aggregates in the gel. In contrast to the hydrogel, the effect of normal bile salt micelles is less dramatic, i.e., bile salt micelles do not lead to significant change in the type of dye aggregation.