Graphene-supported pyrene-functionalized amino-carbon nanotube: a novel hybrid architecture of laccase immobilization as effective bioelectrocatalyst for oxygen reduction reaction

A facile electrochemical method to establish a 3-dimensional architecture of graphene and carbon nanotubes for achieving a highly conductive platform for laccase immobilization is described. By functionalization of a nanostructure with pyrenebutyric acid using an electrochemical treatment, the efficiency of the prepared nanostructure as an electrochemical platform for the oriented adsorption of laccase is enhanced. Electrochemical analyses show that graphene enhances the bioelectrocatalytic activity of immobilized laccase toward the oxygen reduction reaction (ORR). The onset and peak potentials of ORR vs. Ag/AgCl are observed at 0.64 V and 0.45 V, and the peak current density is 1.92 mA cm(-2) (when the electrode rotation speed -> infinity), indicating the improved biocatalytic activity of the proposed system. The proposed methodology might give confidence in the construction of a new generation of enzyme-based biocathodes in mild conditions without using special chemicals or reagents.