Effect of polyion conformation on dye binding. IV. Fluorescence of auramine O in relation to its binding to synthetic polyacids

Abstract

AbstractThe effect of polymer conformation, polymer concentration, and added salt concentration on the quantum yield ϕ of Auramine O (AuO) is discussed in connection with dialysis equilibrium data. The quantum yield per bound dye molecule (ϕ/q) assumes different values which are related principally to solvation changes in the environment of the binding sites. Binding to globular compact a states results in high ϕ/q, whereas low ϕ/q (of the order of magnitude of ϕ of free AuO) are observed for the binding to expanded solvated b states. The quantum yield of bound AuO is therefore affected by the organic nature of the environment, but shows little or no relation to the amount of bound dye molecules.