pH-tunable bioelectrocatalysis based on layer-by-layer films assembled with TiO2 nanoparticles and poly(allylamine hydrochloride)

► {PAH/TiO2}n layer-by-layer films show pH-switchable permeability toward Fe(CN)63-. ► The pH-tunable bioelectrocatalysis of H2O2 by HRP is realized based on the system. ► Electrostatic interaction between the films and the probe decides the mechanism. ► TiO2 nanoparticles play an important role in deciding this pH-sensitive property.