Hemoglobin (Hb) was directly immobilized on a multiwalled carbon nanotubes ionic liquid electrode by immersing this electrode in a solution consisting of Hb and 1-octyl-pyridinium chloride as an ionic liquid. The immobilized Hb displayed a pair of well-defined cyclic voltammetric peaks with a formal potential of0.187 V in acetate buffer solution, pH 5.0. This modified electrode exhibits fast response, a long linearity range, a low detection limit, high stability and excellent sensitivity through hydrogen peroxide detection with a detection limit (3s) of 3.18mM. The electrode was also used for electrocatalysis and voltammetric determination of oxygen and trichloroacetic acid
