There have often been contradications reported in regard to the efficacy of glassy carbon in voltammetric applications. The problem stems from the fact that there are a large variety of carbons available from various manufacturers that vary in their bulk structure, particularly in the degree of compactness. The extent of compactness affects both the bulk and surface properties of glassy carbon. The latter has a bearing on the formation of surface carbon-oxygen functionalities, which influence the electrochemical response of the carbon.