Conductometric glucose biosensor made with cellulose and tin oxide hybrid nanocomposite

This paper reports the feasibility study of glucose oxidase (GO_x) immobilized cellulose-tin oxide (SnO₂) hybrid nanocomposite as a glucose biosensor. Porous SnO₂ layer was grown on regenerated cellulose films via liquid phase deposition technique with varying deposition time. Tin oxide was crystallized in the solution and formed nanocrystal coatings on the cellulose films. Enzyme (GO_x) was immobilized into cellulose-SnO₂ hybrid nanocomposite by physical absorption method. X-ray photoelectron spectroscopy analysis revealed the successful immobilization of GO_x into the cellulose-SnO₂ hybrid nanocomposite via covalent bonding between GO_x and SnO₂. The glucose biosensor under study is displayed linear response in the range of 0.5-12 mM with correlation coefficient of 0.96, which can cover the clinical region of glucose concentration. These results indicate that the cellulose-SnO₂ hybrid nanocomposite can be an inexpensive, flexible and disposable glucose biosensor.