A mediator-free glucose biosensor based on glucose oxidase/chitosan/α-zirconium phosphate ternary biocomposite

A novel glucose oxidase/chitosan/alpha-zirconium phosphate (GOD/chitosan/alpha-ZrP) ternary biocomposite was prepared by co-intercalating glucose oxidase (GOD) and chitosan into the interlayers of alpha-zirconium phosphate (alpha-ZrP) via a delamination-reassembly procedure. The results of X-ray diffraction, infrared spectroscopy, circular dichroism, and ultraviolet spectrum characterizations indicated not only the layered and hybrid structure of the GOD/chitosan/alpha-ZrP ternary biocomposite but also the recovered activity of the intercalated GOD improved by the co-intercalated chitosan. By depositing the GOD/chitosan/alpha-ZrP biocomposite film onto a glassy carbon electrode, the direct electrochemistry of the intercalated GOD was achieved with a fast electron transfer rate constant, k(s), of 7.48 +/- 3.52 s(-1). Moreover, this GOD/chitosan/alpha-ZrP biocomposite modified electrode exhibited a sensitive response to glucose in the linear range of 0.25-8.0 mM (R = 0.9994, n = 14), with a determination limit of 0.076 mM. (C) 2013 Elsevier Inc. All rights reserved.