The present invention provides a novel electrode carrying on at least a portion of its support surface a hybrid polymer matrix (HPM), a catalyst that can catalyze a redox reaction and an optional electron mediator group that enhances the electrical contact between the HPM and the catalyst, the HPM being capable to be electrochemically changed from a non-conductive state to a conductive state. The electrode of the invention may be used in electrical devices such as fuel cells, thus imparting them switchable and tunable properties. The fuel cell of the invention may be used as a power source or as a self-powered sensor.