Precipitated and Chemically-Crosslinked Enzymes over Polyaniline Nanofibers for High Performance Biosensors & Biofuel Cells

Abstract

The enzyme catalysts can be successfully used for bioelectrocatalytic applications such as biosensors, biofuel cells, and even CO2 conversion. However, the short lifetime of enzymes and the slow electron transfer are two critical problems against the practical applications of enzymes in bioelectrocatalysis. Nanobiocatalysis, using conductive nanomaterials for enzyme immobilization, has gathered growing attention due to its recent successes in stabilizing the enzyme activity and expediting the electron transfer. In this study, we employed three different approaches to stabilize glucose oxidase (GOx) and laccase (LAC), which are widely used enzymes for enzymatic biosensors and biofuel cells, on polyaniline nanofibers (PANFs): enzyme adsorption (EA), enzyme adsorption and crosslinking (EAC) and enzyme adsorption, precipitation and crosslinking (EAPC) approaches. Several successful examples of nanobiocatalysis in improving both lifetime and performance of bioelectrocatalytic systems will be introduced in details. Especially, the use of conductive nanomaterials could improve the rate of electron transfer from the enzyme active site to the main electrode.