Novel approach for generating an electrochemically active film with amplification, switching and diode-like behavior

In this work, a new approach to generate a functionalized film on the electrode for molecular diode application is presented. Phenol-grafted chitosan was used as the functionalized film. The anodic oxidation of phenol initiates grafting to the chitosan film and the grafted moieties confer electrochemical activity to the film. Dependent on kinds of mediator, the grafted moieties can serve as an electron donor or electron acceptor and amplify the current in each direction. These results support that the electrochemical activities of modified chitosan are similar to a molecular diode behavior. Also, the electrochemical activity can be quickly restored by electrochemical treatment.