NOVELTY - An electrode comprises a spatial confining structure and an active compound, where the spatial confining structure spatially confines the active compound, and stabilizes the activity of the compound.    USE - As electrode, particularly a silicon, graphite or a carbon paper electrode useful in an electrochemical device selected from an energy-generation device such as a fuel cell, a memory, an electrochemical reactor, a super-capacitor, a biosensor or a medical device or a sensor such as a sensor for detection of a redox reactant selected from methanol, ethanol, glucose, hydrocarbons, alkane, methane, ketone, 3 beta -hydroxybutyrate, phenol, dopamine, lactose and/or fructose, where the fuel cell is a two-compartment fuel cell or a one-compartment membrane-less fuel cell (claimed); and in biomedical and food/beverage applications.    ADVANTAGE - The electrode with a spatial confining structure is used to secure an active compound. By spatially confining the active compound in such structure, the activity of the compound is retained, reserved, stabilized, or deactivated to a less extent. As such, the active compound shows a high degree of resistance against deactivation caused by various conditions. For example, the enzyme/protein shows a high degree of resistance against denaturation caused by various conditions. The spatial confining structure permits the active compound to be accessible from outside the spatial confining structure (semi-open), so that the active compound can function as it is intended.    DETAILED DESCRIPTION - An electrode comprises a spatial confining structure and an active compound, where the spatial confining structure spatially confines the active compound, and stabilizes the activity of the compound. The active compound comprises a biological or organic entity selected from enzymes, DNA, proteins, or polymers; or a redox catalyst that catalyzes a redox reactant selected from methanol, ethanol, glucose, hydrocarbons, alkane, methane, ketone, 3 beta -hydroxybutyrate, phenol, dopamine, lactose, and/or fructose. The redox catalyst comprises an oxidoreductase such as glucose oxidase. The electrode comprises a polymeric material or a generic solid state material such as electrically conductive material selected from metals, semiconductors, superconductors, oxides, or polymers that are used for electrical/electrochemical applications. An INDEPENDENT CLAIM is included for stabilizing the activity of an active compound involving using the electrode comprising a spatial confining structure, where the spatial confining structure spatially confines the active compound.