A steady Hb/PPy/AAO/GC electrode was obtained by successfully immobilizing hemoglobin (Hb) on a glassy carbon (GC) electrode, which was modified using anodic alumina oxide (AAO) films. Its optimum experimental conditions were found. The electrochemistry behavior of the Hb/PPy/AAO/GC biosensor in PBS (pH＝6.8) and the direct electron transfer mechanism of Hb were discussed, finding that the anodic alumina oxide films kept the biological activity of Hb. Moreover through nano-size effect of the films, the direct electron transfer between Hb and the electrode finished. The study is important to life science and clinical medicine.

Key words: hemoglobin, anodic alumina oxide films, chemical modified electrode