The quenched emission for *Ru(bpy)(3)(2+) in the presence of ferrocyanide [Fe(CN)(6)(4-)], was restored in aqueous solutions at pH 8 via the addition of PAMAM dendrimers due to competitive electrostatic binding of the ferrocyanide to the dendrimer. Binding equations were developed assuming a 1:1 interaction between the quencher and a dendrimer binding site size (defined as the number of terminal amine groups). Nonlinear curve fitting of titration data for emission intensity versus added dendrimer at fixed [Fe(CN)(6)(4-)] resulted in calculated values for the binding constants, binding site sizes, and bound quenching rate constants between ferrocyanide and different sized dendrimers. When the PAMAM dendrimer size was increased, the ferrocyanide binding constant increased and the fully bound quenching rate constant decreased, but the binding site size remained the same (between 5 and 6 terminal amines). Changing the buffer from Tris to phosphate at pH 8 dramatically changes the binding parameters as predicted for primarily electrostatic binding. Direct binding studies using solvatochromic 8-anilino-1-naphthalenesulfonic acid (ANS) emission and PAMAM dendrimers indicated a large hydrophobic change going from G3 to G4 that was not seen for ferrocyanide binding. ANS binding constants increased going from pH 6 to 8, which may be explained by the unique protonation behavior and macromolecular topology of PAMAM dendrimers.