Bioinorganic Chemistry on Electrodes: Methods to Functional Modeling

One of the major goals of bioinorganic chemistry has been to mimic the function of elegant metalloenzymes. Such functional modeling has been difficult to attain in solution, in particular, for reactions that require multiple protons and multiple electrons (nH⁺/ne). Using a combination of heterogeneous electrochemistry, electrode and molecule design one may control both electron transfer (ET) and proton transfer (PT) of these nH⁺/ne reactions. Such control can allow functional modeling of hydrogenases (H⁺ + e → 1/2 H₂), cytochrome c oxidase (O₂ + 4 e + 4 H⁺ → 2 H₂O), monooxygenases (RR'CH₂ + O₂ + 2 e + 2 H⁺ → RR'CHOH + H₂O) and dioxygenases (S + O₂ → SO₂; S = organic substrate) in aqueous medium and at room temperatures. In addition, these heterogeneous constructs allow probing unnatural bioinspired reactions and estimation of the inner- and outer-sphere reorganization energy of small molecules and proteins.