earticle

영어

Direct electron transfer (DET) between oxidoreductases and electrode surfaces is very important part in bioelectrocatalysis, which can be applied to electroenzymatic synthesis, electrochemical biosensors, and enzymatic biofuel cells. The DET does not require any mediators between
enzymes and electrodes, eliminating problems related to mediator stability, selectivity, and mass transfer limitations. In addition, DETbased enzyme electrodes theoretically functions at a potential range that is close to the redox potential of the enzyme itself. In this study, the DET of redox enzymes was attempted using two types of immobilization methods: One was enzyme immobilization based on self-assembled monolayers; the other was entrapment with a matrix of
polymers in which conducting nanomaterials such as carbon nanotubes (CNTs) and metal nanoparticles were co-entrapped. As a model enzyme was selected laccase, which is a multicopper oxidase to hold four copper ions and can perform a one-electron oxidation of phenols
and similar molecules with concomitant reduction of molecular oxygen to water. We checked that the DET between laccase and electrodes took place in buffers with different pH values saturated with argon as well as with oxygen using cyclic voltammetry.