Significantly Accelerated Direct Electron‐Transfer Kinetics of Hemoglobin in a C60‐MWCNT Nanocomposite Film

Abstract
The direct electrochemistry of hemoglobin (Hb) was studied in a novel all‐carbon nanocomposite film of C60‐MWCNT (MWCNT=multiple‐walled carbon nanotube) and compared with that in bare MWCNT film. The heterogeneous electron‐transfer rate constant ks of Hb/C60‐MWCNT was determined to be 0.39 s−1, which is more than one order of magnitude greater than that of Hb/MWCNT (0.03 s−1). The significantly accelerated electron‐transfer kinetics are attributed to the mediator role played by C60, which is finely dispersed on the MWCNT surfaces. The excellent stability of Hb/C60‐MWCNT was established and its potential application towards the electrocatalytic reduction of O2 was demonstrated.