In this paper, carbon nanotubes (CNTs) were successfully incorporated in the composite composed of hemoglobin (Hb) and collagen using co-electrospinning technology. The formed Hb-collagen-CNTs composite nanofibers possessed distinct advantage of three-dimensional porous structure, biocompatibility and excellent stability. The Hb immobilized in the electrospun nanofibers retained its natural structure and the heterogeneous electron transfer rate constant (k(s)) of the direct electron transfer between Hb and electrodes was 5.3 s(-1). In addition, the electrospun Hb-collagen-CNTs nanofibers modified electrodes showed good electrocatalytic properties toward H2O2 with a detection limit of 0.91 mu M (signal-to-noise ratio of 3) and the apparent Michaelis-Menten constant (K-m(app)) of 32.6 mu M. (C) 2014 Elsevier B.V. All rights reserved.