A chemical composite useful for preparing a bioelectronic device includes a biologically active compound, such as an enzyme, that is bound directly or indirectly to a polyelectrolyte, which can be reversibly coupled to a chemically treated electrically conductive substrate by electrostatic forces to provide biomimetic sensors, catalyst systems, and other devices having an electrode that can be regenerated and reused. Required or desired cofactors, mediators or the like may be incorporated into the devices, typically by bonding them to the treated substrate and/or the polyelectrolyte.