The diamond membrane was then characterized electrochemically using cyclic voltammetry in a light-protected environment. In order to assess the contribution of the titanium contact, pristine fiberglass filter (without diamond) connected with a similar pattern was characterized through voltammetry in 0.2Mlithiumperchloratewithout redox probe. As expected nomeaningful electrochemical signalwas observed, except a high capacitive current. Cyclic voltammetry has also been carried out in a 2 mM Fe(CN)3−/4− in 0.2 M lithium perchlorate electrolytic solution. Fig. 4b and a depicted voltammograms recorded in the electrolytic solution and in the solution containing 2mMof ferri–ferrocyanide. One can note the high value of the ΔEp observed in Fig. 4a. It has been reported that the oxidized diamond showed a significant decrease of its charge transfer rate constant compared to the hydrogenated one [34]. Oxidation of the surface is also at the origin of the low current densities with ferri–ferrocyanide redox couple, as oxidized BDDs have been shown to give lower current densities when negatively charge redox probes are used [34].