Extending protein-film electrochemistry across enzymology and biological inorganic chemistry to investigate, track and control the reactions of non-redox enzymes and spectroscopically silent metals.

Protein film electrochemistry has helped to unravel many complex reactivities of electron-transferring proteins and enzymes. A versatile descendant, the 'Electrochemical Leaf', offers new opportunities to extend electrochemical control to myriad enzymes that neither transfer electrons nor catalyse any redox reaction, including those dependent on spectroscopically limited, labile or other challenging metal ions. By embedding a cascade comprised of several enzymes-one of which electrochemically recycles NAD(P)(H), a second being a dehydrogenase-within a porous electrode formed from fused nanoparticles, the interconnected reactions are tightly channeled to transmit energy and information, rapidly and interactively. Under nanoconfinement, nicotinamide cofactors and cascade intermediates serve as specific current carriers, far beyond the electron itself.