Direct Electrochemistry of Hemoglobin in Chitosan/Multiwalled Carbon Nanotubes/Ionic Liquid–Modified Carbon-Paste Electrode

Abstract The direct electrochemistry of hemoglobin (Hb) was realized on chitosan and multiwalled carbon nanotubes (MWCNTs)–modified carbon ionic liquid electrode (CILE). The CILE was fabricated first and further modified by MWCNTs to get an electrode as MWCNTs/CILE. The Hb was immobilized on the surface of MWCNTs/CILE with the help of chitosan film. Ultraviolet–visible (UV-vis) and Fourier transform–infrared (FT-IR) spectra indicated that Hb kept its native structure in the modified film. A pair of well-defined quasi-reversible redox peaks of heme Fe(III)/Fe(II) couple appeared with the formal potential (E0′) as −0.314 V (vs. SCE) in pH 7.0 phosphate buffer solution (PBS). The modified electrode showed good electrocatalytic ability for the reduction of trichloroacetic acid.