Apo-glucose oxidase was reconstituted onto a pyrroloquinoline quinone and flavin adenine dinucleotide phosphate (PQQ–FAD) monolayer associated with a rough Au electrode to yield a bioelectrocatalytically active glucose oxidase, GOx. An electrically contacted PQQ–FAD/GOx monolayer was applied for the biocatalytic oxidation of glucose in an aqueous electrolyte. Microperoxidase-11, MP-11, was assembled as a monolayer on a rough Au electrode and used for the biocatalytic reduction of cumene peroxide in a dichloromethane electrolyte solution. Both biocatalytic electrodes, Au/PQQ–FAD/GOx and Au/MP-11, were integrated into one system, creating a biofuel cell using glucose and cumene peroxide as the fuel substrate and the oxidizer, respectively, in a two-phase liquid system. The biofuel cell generates an open-circuit voltage, V_oc, of ca. 1 V and a short-circuit current density, i_sc, of ca. 830 µA cm^-2. The maximum electrical power, W_max, extracted from the cell is 520 µW at an external optimal load of 0.4 kΩ. The fill factor of the biofuel cell, f=W_max · I_sc^-1 · V_oc^-1, is ca. 25%. The biofuel cell based on bioelectrocatalytic processes in two immiscible electrolytes shows a significant increase of the evaluated power in comparison with similar electrocatalytic systems in a single-phase aqueous electrolyte.