Electrochemical processes mediated via adsorbed Enzymes: Flat and porous electrodes Compared. Understanding Nano-confinement

We present theory for electrolysis at electrode surfaces modified by a layer of electroactive enzyme which can mediate the reduction of a substrate to a product. In particular, we compare and contrast immobilisation on flat surfaces with that on porous surfaces. We identify the conditions under which the adoption of porous electrodes facilitates markedly improves turnover rates and develop the analysis on the basis of the porous layer conferring a much-increased effective surface coverage. For both types of electrode, the role of the electrode potential in controlling the thermodynamics of the binding of the substrate with the reduced layer of immobilised enzymes is quantified, and the observation of apparent potential dependent Michaelis constants are explained. Four distinct classes of voltammetric responses are categorised allowing bottom-up process optimisation.

Automated summary

This study presents a theory for electrolysis at electrode surfaces modified by an electroactive enzyme layer, comparing immobilization on flat and porous surfaces. The use of porous electrodes is found to significantly improve turnover rates due to increased effective surface coverage. The role of electrode potential in controlling thermodynamics of substrate binding and the observation of potential dependent Michaelis constants are quantified, allowing for process optimization based on four distinct classes of voltammetric responses.