Abstract
We report on improvement of sensitivity for molecular detection utilizing terahertz time domain spectroscopy. Based on confining and enhancing electromagnetic field with metallic nanoslot antennas, we additionally employ monolayer graphene sheet whose edge and hydrophobic surface nature lead to increase detecting performance. Terahertz transmittance in monolayer graphene/metallic nanoslot structure exhibits more unambiguous change after lactose molecules are attached, compared to that in metallic nanoslot structure without monolayer graphene. We attribute the prominent change to that more lactose molecules are guided inside/near the metal gap region due to edge and hydrophobic surface nature of monolayer graphene. This monolayer graphene/metallic nanoslot structure can be expanded in other organic or bio-molecular detection.