This proposal concerns the adsorption behaviour of a key electron-transfer species, NADH, found in many cells as well as in bioelectrochemical devices used to capture light energy, on two important electrode surface types—glassy carbon and stainless steel. We are particularly interested how the structure of the adsorbed species changes upon variation of applied potential, with the ultimate aim of improving understanding of the electron transfer mechanisms at these interfaces. Previous electrochemical measurements have implied that NADH molecules may behave rather interestingly and change their adsorption structure (e.g. flat vs standing upright, monomer adsorption vs dimer) depending on both the solution conditions and applied potential. Neutron reflectometry offers a unique opportunity to verify (or contradict) these hypotheses.