Direct electrochemistry and electrocatalysis of hemoglobin entrapped in semi-interpenetrating polymer network hydrogel based on polyacrylamide and chitosan

作者：Zeng, Xiandong; Wei, Wanzhi^*; Li, Xuefang; Zeng, Jinxiang; Wu, Ling

来源：Bioelectrochemistry, 2007, 71(2): 135-141.

DOI：10.1016/j.bioelechem.2007.02.006

• hemoglobin
• direct electrochemistry
• electrocatalysis
• polyacrylamide
• chitosan
• semi-interpenetrating polymer network hydrogel

Semi-interpenetrating polymer network (semi-IPN) hydrogel based on polyacrylamide (PAM) and chitosan was prepared to immobilize redox protein hemoglobin (Hb). The Hb-PAM-chitosan hydrogel film obtained has been investigated by scanning electron microscopy (SEM) and UV-VIS spectroscopy. UV-VIS spectroscopy showed that Hb kept its secondary structure similar to its native state in the Hb-PAM-chitosan hydrogel film. Cyclic voltammogram of Hb-PAM-chitosan film-modified glass carbon (GC) electrode showed a pair of well-defined and quasi-reversible redox peaks for Hb Fe(III)/Fe(II), indicating that direct electron transfer between Hb and GC electrode occurred. The electron-transfer rate constant was about 5.51 s(-1) in pH 7.0 buffers, and the formal potential (E-o') was -0.324 V (vs. SCE). The dependence of E-o' on solution pH indicated that one-proton transfer was coupled to each electron transfer in the direct electron-transfer reaction. Additionally, Hb in the semi-IPN hydrogel film retained its bioactivity and showed excellent electrocatalytic activity toward H2O2. The electrocatalytic current values were linear with increasing concentration of H2O2 in a wide range of 5-420 mu M. The unique semi-IPN hydrogel would have wide potential applications in direct electrochemistry, biosensors and biocatalysis.

• 出版日期2007-11
• 单位湖南大学