Abstract: | Herein, we demonstrate that the intramolecular electron transfer within a single enzyme molecule is an important alternative pathway that can be harnessed to generate electricity. By decoupling the redox reactions within a single type of enzyme (for example, Trametes versicolor laccase), we harvested electricity efficiently from unconventional fuels including recalcitrant pollutants (for example, bisphenol A and hydroquinone) in a single‐laccase biofuel cell. The intramolecular electron‐harnessing concept was further demonstrated with other enzymes, including power generation during CO2 bioconversion to formate catalyzed by formate dehydrogenase from Candida boidinii . The novel single‐enzyme biofuel cell is shown to have potential for utilizing wastewater as a fuel as well as for generating energy while driving bioconversion of chemical feedstock from CO2. |