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제목 | [논문] 안영환 - Terahertz virus-sized gold nanogap sensor | ||
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등록일 | 2023-01-16 | 조회수 | 278 | |
Terahertz virus-sized gold nanogap sensor by Gangseon Ji; Hwan Sik Kim; Seong Ho Cha; Hyoung-Taek Lee; Hye Ju Kim; Sang Woon Lee; Kwang Jun Ahn; Kyoung-Ho Kim; Yeong Hwan Ahn, Hyeong-Ryeol Park Nanophotonics 2023 https://doi.org/10.1515/nanoph-2022-0706
Abstract We demonstrated an ultra-sensitive terahertz virus detection method combined with virus-sized gold nanogaps filled with Al2O3. Large-area highdensity 20 nm-gap rectangular loop structures, containing a resonant frequency in the terahertz range, were fabricated on a 4-inch wafer using atomic layer lithography. When target viruses with a 60 nm diameter were located on the nanogaps, we observed a significant redshift of the resonant peak already with an average number of about 100 viruses per unit loop due to the strong field confinement and enhancement near the gap. Furthermore, when the virus was tightly attached to an etched gap like a bridge connecting metals, its sensitivity is doubled compared to the unetched gap, which resulted in 400% more resonance frequency shift per single virus particle than our previous work. Full-wave simulations and theoretical calculations based on modal expansions were in good agreement with the experiments, revealing that the resonant transmission spectrum was mostly determined by the change in refractive index in a two-dimensional-like optical hotspot near the nanogap. A further step could be taken to increase sensitivity by tuning nanogap-loops to the absorption frequencies associated with the intermolecular vibrational modes of the viruses and fingerprinting them as well.
Keywords: atomic layer lithography; nanogap; refractive index sensing; terahertz sensing; terahertz time-domain spectroscopy; virus |
이전 | [논문] 안영환 - High-Speed THz Time-of-Flight Imaging with Reflective Optics |
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다음 | [논문] 안영환 - Terahertz Nondestructive Time-of-flight Imaging with a Large Depth Range |