Immobilization of Glucose Oxidase within Chitosan and Sol-Gel Matrix for Biosensors

Abstract

Enzyme-modified electrodes were fabricated by entrapping glucose oxidase (GOx) and ferrocene (Fc) using chitosan membrane and sol-gel matrix. In chitosan membrane entrapment method, the ferrocene and glucose oxidase were coated sequentially on a glassy carbon electrode and entrapped by chitosan. In sol-gel matrix method, the ferrocene and glucose oxidase were embedded into sol-gel matrix without using any complicated linking processes. The prepared electrode was characterized by cyclic voltammetry (CV). Both Fc/GOx/CHI electrode and Fc/GOx/Sol-gel exhibited a good electrochemical performance for the glucose analysis. The response current of the both Fc/GOx/CHI and Fc/GOx/Sol-gel electrodes increased linearly with the increase of glucose concentration in the range of 0–10 mM glucose. The apparent Michaelis-Menten constants (Km) for the enzymes immobilized in the chitosan membrane and sol-gel matrix were observed to be 1.67 mM and 12.59 mM, respectively. The maximum current of the Fc/GOx/CHI and Fc/GOx/Sol-gel electrodes were 5.85 μA and 7.52 μA, respectively.

Keywords:

• Ferrocene; Glucose oxidase
• Chitosan
• Sol-gel
• Glucose sensor

Acknowledgments

This work was supported by the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 20104010100510) and by the Gyeonggi Regional Research Center.