PH‐Switchable Redox Reactions and Bioelectrocatalytic Processes Using Au Nanoparticles‐Modified Electrodes

Abstract

AbstractBoronate ester complexes generated between methylene blue (MB+)‐functionalized Au nanoparticles (NPs) and electrode surfaces are implemented to stimulate the bioelectrocatalyzed reduction of H2O2 in the presence of horseradish peroxidase (HRP). Two kinds of Au NPs are prepared: Class I includes MB+/phenylboronic acid as a modifying layer, whereas Class II includes MB+/dithiothreitol as a mixed capping layer. The Class I or II NPs form boronate ester complexes with a dithiothreitol‐ or phenylboronic acid‐functionalized Au electrodes, respectively. By the cyclic loading of the NPs on the electrodes (pH 8.1), and the removal of the NPs (pH 1.5), switchable bioelectrocatalyzed reduction of H2O2 is demonstrated.