Immobilized polymerized electroactive vesicles (IPEVs) are biocapsules capable of storing charge in confined environments and of chemisorbing on conductive metal surfaces. Methods to immobilize stable electroactive vesicles and the means to measure their electroactivity at nanocoulomb levels are demonstrated. Charge transport between the electrode surface and the vesicle interior is tuned by adjusting the concentration of a membrane-soluble electron mediator. IPEVs serve as a model for developing biomimetic systems intended for charge storage and electron coupling applications.