Electrochemical sensing based on hemin-ordered mesoporous carbon nanocomposites for hydrogen peroxide

Abstract

The highly ordered mesoporous carbon (OMC) was used for the immobilization of hemin, and the electrochemical and electrocatalytic properties of the hemin–OMC nanocomposites modified electrode were studied. The interaction between hemin and OMC was investigated by using UV-vis spectroscopy, nitrogen adsorption isotherm, and cyclic voltammetry. UV-vis absorption spectra display that hemin keeps almost natural structure in the OMC matrix. The CV results of hemin–OMC modified electrode showed a pair of well-defined and quasi-reversible redox peaks centered at approximate −0.345 V (vs. SCE) in pH 7.0 phosphate buffer solution. Furthermore, the hemin–OMC modified electrode displayed good electrocatalytic responses to the reduction of hydrogen peroxide (H₂O₂), which had a linear range from 2.0 × 10⁻⁶ to 2.5 × 10⁻⁴ M (R = 0.9992, n = 12) with the detection limit of 0.3 μM (S/N = 3).