Enyzyme-Immobilized Electrode Prepared Using Cellulose Nanofiber

Abstract

Various procedures have been proposed for the preparation of enzyme-immobilized electrode, such as covalent attachment, cross-linking, hydrogel entrapment, polymer film entrapment, and the combination of two or more methods.Cellulose is a linear polysaccharide of glucose, which have significant high strength and stability due to strong intra- and inter-molecular hydrogen bonds within and among individual chains. Cellulose nanofiber (CNF) dispersion solution can be obtained by stripping down water insoluble cellulose fibers using procedures such as wet jet milling. In this study, CNF was applied for the immobilization of enzyme by entrapping it within CNF matrix. Glucose oxidase (GOx) was employed as the enzyme, and GOx-CNF immobilized electrodes were fabricated by simple repetitious drops of cellulose solution containing GOx on the surface of an electrode. The obtained electrode provided a glucose sensor with significantly high response speed and good linear relationship between glucose concentration and response current. Introduction of CNF films on GOx-CNF film successfully reduced the release of GOx from enzyme-immobilized electrode and glucose sensor with good long term stability was obtained.