H₂O₂-induced decomposition of layer-by-layer films consisting of phenylboronic acid-bearing poly(allylamine) and poly(vinyl alcohol)

Layer-by-layer (LbL) films were prepared by an alternate deposition of phenylboronic acid-bearing poly(allylamine hydrochloride) (PBA-PAH) and poly(vinyl alcohol) (PVA) on the surface of a quartz slide to develop thin films that can be decomposed in response to hydrogen peroxide (H₂O ₂). The PBA-PAH/PVA films decomposed in the presence of H ₂O₂; the degree and kinetics of decomposition depend on the concentration of H₂O₂ and on the pH of the solution. For example, the film decomposition completely occurred in 30 min in 1.0 mM H₂O₂ solution at pH 7.4, while it took 180 min in 0.1 mM H₂O₂ solution. The H₂O₂-induced decomposition of the film can be explained in terms of the oxidative scission of the carbon-boron bond in PBA residues in the PBA-PAH chains. A potential use of the PBA-PAH/PVA films in developing H₂O₂-sensitive delivery systems was suggested.