Comparative electrochemistry of haemoglobin on the long and ball milling shortened carbon nanotubes

Abstract

Short multi-walled carbon nanotubes (S-MWCNTs) were obtained by ball milling method and employed as a supporting matrix to explore a novel immobilisation and biosensing platform of redox proteins such as haemoglobin (Hb). Compared to long MWCNTs, the shortened MWCNTs-based biosensor did not show better electrocatalytic activity, which was contrary to previous theoretical expectations. The electron transfer rate constants of Hb on long and short MWCNTs modified electrodes in phosphate buffer solution were 1.08 and 0.95 s-1, respectively. The lower electron transfer rate between haemoglobin and the electrode can be attributed to their larger resistive properties, which were confirmed by cyclic voltammetry and AC impedance. © 2014 Copyright Taylor and Francis Group, LLC.