Electrochemical fingerprint of cytochrome c on a polymer/MWCNT nanocomposite electrode

The electroactivity of cytochrome c on screen-printed graphite electrodes modified with stable dispersions of multi-walled carbon nanotubes in aqueous solution of amphiphilic poly(n-butyl acrylate)₁₀₀-block-poly(acrylic acid)₁₄₀ diblock copolymers was estimated. Using a broad potential window, the reduction and oxidation of heme iron at a near-zero potential, the electrooxidation of Tyr and Trp at +0.6V and the electrooxidation of heme at +0.8V were detected in a wide concentration range of 1–100μm with a limit of detection of 1–2μm. Such a multipoint detection can be used as an electrochemical fingerprint of cytochrome c for its electrochemical recognition and quantification in complex (bio)chemical analytes.