“…6 The flavins have in common the isoalloxazine ring system where the redox process occurs, Figure 1b. The nature of the group attached to the N-10, Figure 1a, is the flavin members differentiation and can influence the flavin adsorption orientation on the electrode surface, 7,8 leaving the active site more or less available. The redox process of the flavins is thermodynamically reversible, irrespective of whether one or two electrons per flavin molecule are being transferred, which means that their redox states (quinone state, semiquinone state, hydroquinone state) must be considered.…”