摘要： We report that single-stranded deoxyribonucleic acids (ssDNAs) at very low concentrations can be detected using graphene-combined nano-slot-based terahertz (THz) resonance. A combination of the resonant structure and tuned electro-optical properties of graphene can provide unprecedentedly sensitive biomolecule sensing even using very low energy THz photons, overcoming the huge scale di?erence of 10,000:1 between the wavelength and the size of the ssDNAs. Ultrahigh sensitivity is obtained by the signi?cant increase in the absorption cross-section of the graphene sheet with the targeted biomolecules, induced by strong THz ?eld enhancement at the resonance frequency inside the slots. Clearly distinguishable THz optical signals were observed between di?erent species of ssDNAs even at the nano-mole level and analyzed quantitatively in terms of the electro-optical properties of the suspended graphene layer modi?ed by the attached ssDNAs without any molecular-speci?c labeling for the THz regime. Quantitative analysis of ssDNA molecule adsorption was carried based on the change in conductivity using a theoretical THz transmission model.