Electrical conductivity of an anhydrous cytochrome c3 film as a function of temperature and ambient pressure

Abstract The electrical conductivity of anhydrous films of cytochrome c 3 containing a trace of hydrogenase as a reducing catalyst was measured in the temperature region from 230 to 383 K, where cytochrome C 3 changes from the ferrous to the ferric state under a hydrogen atmosphere. The value of the electrical resistivity of ferrocytochrome c 3 reached 8 Ω cm at the minimum at 286 K. The activation energies of the resistivity for ferri- and ferro-cytochrome c 3 are 1.55 and 2.15 eV, respectively. Further, the conductivity of this film was also measured as a function of hydrogen pressure at 296 K. As a relation between the hydrogen pressure ( P ) and the electric current ( I ), we obtained I = a ( P / P o ) 3 , where P 0 = 100 kPa. This relation agrees with the results of our previous work.