Lee, Sang-Hun Choe, Jong-Ho Kim, Chulki Bae, Sukang Kim, Jin-Soo Park, Q-Han Seo, Minah 2024-01-19T17:32:54Z 2024-01-19T17:32:54Z 2021-09-04 2020-05-01 0925-4005 https://pubs.kist.re.kr/handle/201004/118641 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 difference of 10,000:1 between the wavelength and the size of the ssDNAs. Ultrahigh sensitivity is obtained by the significant increase in the absorption cross-section of the graphene sheet with the targeted biomolecules, induced by strong THz field enhancement at the resonance frequency inside the slots. Clearly distinguishable THz optical signals were observed between different species of ssDNAs even at the nano-mole level and analyzed quantitatively in terms of the electro-optical properties of the suspended graphene layer modified by the attached ssDNAs without any molecular-specific 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. English ELSEVIER SCIENCE SA INFRARED-SPECTROSCOPY DNA MOLECULES ABSORPTION TRANSISTOR NANOSCALE Graphene assisted terahertz metamaterials for sensitive bio-sensing Article 10.1016/j.snb.2020.127841 1 SENSORS AND ACTUATORS B-CHEMICAL, v.310 SENSORS AND ACTUATORS B-CHEMICAL 310 scie scopus 000519306300029 2-s2.0-85079228320 Chemistry, Analytical Electrochemistry Instruments & Instrumentation Chemistry Electrochemistry Instruments & Instrumentation Article INFRARED-SPECTROSCOPY DNA MOLECULES ABSORPTION TRANSISTOR NANOSCALE Metamaterial Terahertz Biosensor Graphene