A donor/acceptor system was designed to measure the bimolecular electron transfer (ET) rate constant from a donor in the aqueous phase to an acceptor anchored to the micellar surface utilizing a simple kinetic formalism. In this system, the donor, Ru(phen)(2)bps (phen = 1,10-phenanthroline, bps = disulfonated 4,7-dipheriyl-1,10-phenanthroline), possesses an overall zero charge and does not associate with anionic or neutral surfactants, whereas the C7C7V2+ (1,1＇-diheptyl 4,4＇-viologen) acceptor is anchored to the micellar surface through the heptyl chains, in water, the formation of a ground-state aggregate between Ru(phen)(2)bps and C7C7V2+ results in biexponential decay of the emission of the probe in the presence of quencher. The bimolecular quenching of Ru(phen)(2)bps by C7C7V2+ takes place with k(q) = 3.0 x 10(9) M-1 s(-1), in agreement with that measured for the related C1C1V2+ (methyl viologen) 4.8 x 10(9) M-1 s(-1), where no aggregation was observed. Within the Ru(phen)(2)bps-C7C7V2+ aggregate the excited state of the complex is quenched with a rate of similar to 6.3 x 10(6) s(-1), The emission decay of *Ru(phen)(2)bps remains monoexponential in the presence of anionic SDS (sodium dodecyl sulfate) micelles, but becomes biexponential upon addition of C7C7V2+. The short- and long-lifetime components have been interpreted as the reaction of aqueous *Ru(phen)(2)bps with C7C7V2+ either residing in the aqueous phase or bound to SDS (k(q) = 8.0 x 10(7) M-1 s(-1)). The bimolecular quenching by C7C7V2+ bound to the surface of SDS micelles is similar to 30 times slower than in water and bound to neutral C12E8 (n-dodecyl octaoxyethylene glycol monoether) micelles (2.6 x 109 M-1 s(-1)). Several possible explanations for the difference in the observed rates when the acceptor is bound to the SDS micellar surface are provided.