Direct electrochemistry and electrocatalysis of myoglobin in dodecyltrimethylammonium bromide film modified carbon ceramic electrode

Direct electrochemistry and electrocatalysis of myoglobin (Mb) were studied with Mb immobilized on dodecyltrimethylammonium bromide (DTAB) film modified carbon ceramic (CC) electrode. Cyclic voltammetry showed a pair of well-defined and nearly reversible redox peaks of Mb (FeII/FeIII) at about −0.3 V vs. SCE (pH = 6.98). The currents of the redox peak were linear to scan rate, and rate constant (Ks) was estimated to be 3.03 s−1. The formal potential (E°′) of Mb in the DTAB/CC electrodes shifted linearly with pH with a slope of −36.44 mV/pH, implying that the electron transfer between DTAB and CC electrodes is accompanied by proton transportation. The immobilized Mb exhibited excellent electrocatalytic response to the reduction of hydrogen peroxide (H2O2).