ELECTROACTIVE MYOGLOBIN-SURFACTANT FILMS IN A BICONTINUOUS MICROEMULSION

Films cast from DDAB microemulsions containing the protein myoglobin (Mb) onto pyrolytic graphite electrodes gave good electron-transfer properties when used in these same microemulsions, The films became thinner during the first 10 min after initial insertion into the microemulsion. A film <1 mu m thick remained on the surface of the electrode in DDAB microemulsions and exhibited direct electron transfer between the electrode and the Fe(III)/Fe(II) redox couple of myoglobin. Mb-DDAB films could be used for nearly a week in an unstirred DDAB/water/dodecane (13/28/59) microemulsion. The position of the Soret electronic absorbance band suggests that Mb in these films is partly denatured. Mb-DDAB films were used to facilitate redox reactions of polar and nonpolar solutes in DDAB microemulsions, as illustrated by reductions of the polar trichloroacetic acid and the nonpolar oxygen.