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

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 x 10(-6) to 2.5 x 10(-4) M (R = 0.9992, n = 12) with the detection limit of 0.3 mu M (S/N = 3).