Glucose Oxidase-graphene-chitosan modified electrode for direct electrochemistry and glucose sensing

Citation:

Kang, X. H. ; Wang, J. ; Wu, H. ; Aksay, I. A. ; Liu, J. ; Lin, Y. H. Glucose Oxidase-graphene-chitosan modified electrode for direct electrochemistry and glucose sensing. Biosensors & Bioelectronics 2009, 25, 901-905.

Date Published:

Dec

Type of Article:

Article

ISBN Number:

0956-5663

Accession Number:

WOS:000272439800039

Abstract:

Direct electrochemistry of a glucose oxidase (GOD)-graphene-chitosan nanocomposite was studied. The immobilized enzyme retains its bioactivity, exhibits a surface confined, reversible two-proton and two-electron transfer reaction, and has good stability, activity and a fast heterogeneous electron transfer rate with the rate constant (k(s)) of 2.83 s(-1). A much higher enzyme loading (1.12 x 10(-9) mol/cm(2)) is obtained as compared to the bare glass carbon surface. This GOD-graphene-chitosan nanocomposite film can be used for sensitive detection of glucose. The biosensor exhibits a wider linearity range from 0.08 mM to 12 mM glucose with a detection limit of 0.02 mM and much higher sensitivity (37.93 mu A mM(-1) cm(-2)) as compared with other nanostructured supports. The excellent performance of the biosensor is attributed to large surface-to-volume ratio and high conductivity of graphene, and good biocompatibility of chitosan, which enhances the enzyme absorption and promotes direct electron transfer between redox enzymes and the surface of electrodes.