Myoglobin immobilized on mesoporous carbon foam in a hydrogel (selep) dispersant for voltammetric sensing of hydrogen peroxide

Mesoporous carbon foam (MCF) was prepared by via the Pechini method which is facile and template-free. The MCF was characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and BET surface area analysis. Afterwards, the MCF was dispersed in the natural hydrogel salep to give a composite. Finally, myoglobin was immobilized on the composite and then placed on a glassy carbon electrode (GCE). The modified GCE gives a distinct quasi-reversible redox peak during electroreduction of hydrogen perxide (H2O2). The estimated electron transfer coefficient (a) and the heterogeneous electron transfer rate constant (ks) for redox process of Mb are 0.54 and 2.25 s(-1), respectively. The sensor, best operated at -0.2 V (vs. Ag/AgCl), responds to H2O2 in the 1.0 to 80 mu M H2O2 concentration range, with a 180 nM limit of detection (at S/N ratio of 3). The technique was applied to the determination of H2O2 in spiked fetal bovine serum samples.