Direct electrochemistry and electrocatalysis of hemoglobin protein entrapped in graphene and chitosan composite film.

A novel, biocompatible sensing strategy based on graphene and chitosan composite film for immobilizing the hemoglobin protein was firstly adopted. The direct electron transfer and bioelectrocatalytic activity of hemoglobin after incorporation into the composite film were investigated. A pair of reversible redox waves of hemoglobin was appeared, and hemoglobin could exhibit its bioelectrocatalytic activity toward H(2)O(2) in a long term. Such results indicated that graphene and chitosan composite could be a friendly biocompatible interface for immobilizing biomolecules and keeping their native structure. Furthermore, the appearance of graphene in the composite film could facilitate the electron transfer between matrix and the electroactive center of hemoglobin. Hence, this graphene and chitosan based protocol would be a promising platform for protein immobilization and biosensor preparation. (c) 2010 Elsevier B.V. All rights reserved.