Encapsulated Laccases as Effective Electrocatalysts for Oxygen Reduction Reactions

The efficient electronic wiring of silica-encapsulated laccases has been applied for the first time to the bioelectrocatalytic reduction of oxygen. The synthesized silica/laccase composites were evaluated electrochemically and characterized by UV-vis, Fourier transform infrared (FT-IR), dynamic light scattering, and X-ray photoelectron spectroscopy. FT-IR measurements showed that laccase preserved its native-like structure after the biosilicification process. The one-pot biosilicification synthesis facilitated the accommodation of the enzymes in highly effective orientations for the direct electron transfer of the T1 redox centers. Consequently, the biosilicified laccase deposited on Ni electrodes exhibited an efficient bioelectrocatalytic oxygen reduction, with current densities of up to 0.94 mA/cm2. Copyright © 2018 American Chemical Society.