Electrochemistry and Electrocatalysis of Myoglobin Loaded into Multilayer Films Assembled with Phytic Acid and Chitosan

Natural polymer polysaccharides chitosan (CS) was successfully assembled with phytic acid (PA) into {PA/CS}(n) layer-by-layer films. Myoglobin (Mb) could be gradually "absorbed" or loaded into {PA/CS}(n) films when the films were immersed into Mb solutions, forming {PA/CS}(n)-Mb films. The {PA/CS}(n)-Mb films demonstrated well-defined and quasi-reversible cyclic voltammetry (CV) responses for Mb Fe-III/Fe-II redox couple and were used to catalyze electrochemical reduction of oxygen and hydrogen peroxide. The interaction between Mb and {PA/CS}(n) films was explored and discussed, which suggested that the electrostatic attraction might play a major role in loading Mb into the films. This new kind of film incorporated with redox proteins could be used to fabricate the new type of biosensors or bioreactors without using mediators.