Interaction between Enzymes and Carbon Nanomaterialsfor Nanobiocatalysis

Abstract

Carbon nanomaterials such as carbon nanotubes (CNTs) and graphene oxides (GROs) have gathered great attention due to their unique physical, chemical and electrical properties. However, the poor dispersion of hydrophobic carbon nanomaterials in hydrophilic aqueous solution makes their versatile uses difficult. As a solution, CNTs are usually treated with strong acids to be dispersed in aqueous solution, but the acid treatment of CNTs is not only tedious and time-consuming but also causes structural defects that can seriously impair the electrical conductivity of CNTs. This presentation will introduce the simple dispersion of CNTs into an enzyme solution, which enables a new nanobiocatalytic approach for the immobilization and stabilization of enzymes. The good dispersion of CNTs in the enzyme solution can be explained by the amphiphilic nature of enzyme’s surface, where hydrophobic moieties interact with the hydrophobic carbon surface while hydrophilic moieties interact with the aqueous solution. Based on effective dispersion of CNTs without acid treatment, we have developed stable form of nanobiocatalyst using glucose oxidase, which was successfully employed for electrochemical biosensors and biofuel cells, respectively. It is anticipated that this newly-developed protocol of nanobiocatalysis based on the simple dispersion of CNTs in aqueous enzyme solution can be easily employed for many other combinations of enzymes and carbon nanomaterials in order to achieve successes in various electrochemical enzyme applications. Keywords: Nanobiocatalysis, Carbon nanotubes, Glucose oxidase, Biosensors, Biofuel cells