MOLECULAR RECOGNITION BY HYDROGEN-BONDING IN POLYELECTROLYTE MULTILAYERS

Functional polyanions were prepared by copolymerization of sulfopropyl acrylate and sulfopropyl methacrylate with monomers bearing triaminop yrimidine or barbituric acid functionalities, respectively. Functional ized polyelectrolyte multilayers were assembled from these copolymers by stepwise alternating adsorption with poly(choline methacrylate). Th ese multilayers are suited for molecular recognition of substrates tha t are complementary to the functional groups incorporated. Thus, multi layers containing triaminopyrimidine moieties selectively bind barbitu ric acid, and vice versa, when exposed to solutions of the 1:1 complex of barbituric acid and triaminopyrimidine. The molecular recognition process was monitored by UV/Vis spectroscopy, time-of-flight secondary ion mass spectroscopy (ToF-SIMS), and photoelectron spectroscopy (XPS ). Remarkably, after successful recognition and binding of the complem entary substrates to the mutilayers, the stepwise layering could be co ntinued.