With greater security and humanitarian concerns, the pressing need to develop fast and sensitive point-of-care explosives detectors has never been more pronounced. Electrochemical detectors facilitate accurate and swift detection of these explosive traces to provide opportunities for preemptive measures. Sensitivity of the electrode material is one of the many important factors in the development of an effective and efficient electrochemical detector. Herein, we present study on the applicability of graphene and hydrogenated graphene for the detection of TNT in seawater. Graphene was found to display a higher sensitivity than hydrogenated graphene and could be an ideal material for the detection of TNT in seawater. This is likely due to the fact that graphene contains a larger amount of aromatic rings than hydrogenated graphene, enabling larger preconcentration. These finding are of high importance to the application of graphene-based materials for explosives detection.