Monolayer molecular sensing using infrared leaky waveguide mode
Surface-enhanced infrared absorption spectroscopy is attractive for molecular sensing due to its access to chemical bonds with high detection sensitivity. Such a spectroscopic method typically operates on localized resonances in subwavelength structured antennas and metamaterials. In this paper, we...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
AIP Publishing LLC
2021-03-01
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| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/5.0039597 |
| _version_ | 1818333056601161728 |
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| author | Tieyan Zhang De He Lu Liu Qiqige Wulan Jiachen Yu Zhe Li Zhijun Liu |
| author_facet | Tieyan Zhang De He Lu Liu Qiqige Wulan Jiachen Yu Zhe Li Zhijun Liu |
| author_sort | Tieyan Zhang |
| collection | DOAJ |
| description | Surface-enhanced infrared absorption spectroscopy is attractive for molecular sensing due to its access to chemical bonds with high detection sensitivity. Such a spectroscopic method typically operates on localized resonances in subwavelength structured antennas and metamaterials. In this paper, we demonstrate monolayer octadecanethiol detection by using the leaky guided mode in a metal–insulator–metal waveguide, whose angle-tunable dispersion enables coupling to molecular vibrations with a frequency-variable optical resonance. Our results show that, by changing the incident angle from 15° to 75°, the resonance frequency of the leaky guided mode is scanned around the CH2 vibration modes with frequency detuning from −200 cm−1 to 350 cm−1 in wavenumber. As the frequency detuning increases, the vibration signal of both the CH2 symmetric and asymmetric modes increases first and then decreases. The maximum vibration signal of 1%–1.5% is reached at positive and negative frequency detuning values of ±100 cm−1. These sensing properties are explained with a coupled-oscillator model, which suggests that both enhanced near-field and coupling strength between the optical resonance and molecular vibration play an important role for the optimal sensing performance. |
| first_indexed | 2024-12-13T13:45:34Z |
| format | Article |
| id | doaj.art-252559cab4c04f14aaa8a6a95fdd216f |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-12-13T13:45:34Z |
| publishDate | 2021-03-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-252559cab4c04f14aaa8a6a95fdd216f2022-12-21T23:43:25ZengAIP Publishing LLCAIP Advances2158-32262021-03-01113035305035305-710.1063/5.0039597Monolayer molecular sensing using infrared leaky waveguide modeTieyan Zhang0De He1Lu Liu2Qiqige Wulan3Jiachen Yu4Zhe Li5Zhijun Liu6School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, ChinaCollege of Electronic and Information Engineering, Southwest University, Chongqing 400715, ChinaSchool of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, ChinaSchool of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, ChinaSchool of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, ChinaSchool of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, ChinaSchool of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, ChinaSurface-enhanced infrared absorption spectroscopy is attractive for molecular sensing due to its access to chemical bonds with high detection sensitivity. Such a spectroscopic method typically operates on localized resonances in subwavelength structured antennas and metamaterials. In this paper, we demonstrate monolayer octadecanethiol detection by using the leaky guided mode in a metal–insulator–metal waveguide, whose angle-tunable dispersion enables coupling to molecular vibrations with a frequency-variable optical resonance. Our results show that, by changing the incident angle from 15° to 75°, the resonance frequency of the leaky guided mode is scanned around the CH2 vibration modes with frequency detuning from −200 cm−1 to 350 cm−1 in wavenumber. As the frequency detuning increases, the vibration signal of both the CH2 symmetric and asymmetric modes increases first and then decreases. The maximum vibration signal of 1%–1.5% is reached at positive and negative frequency detuning values of ±100 cm−1. These sensing properties are explained with a coupled-oscillator model, which suggests that both enhanced near-field and coupling strength between the optical resonance and molecular vibration play an important role for the optimal sensing performance.http://dx.doi.org/10.1063/5.0039597 |
| spellingShingle | Tieyan Zhang De He Lu Liu Qiqige Wulan Jiachen Yu Zhe Li Zhijun Liu Monolayer molecular sensing using infrared leaky waveguide mode AIP Advances |
| title | Monolayer molecular sensing using infrared leaky waveguide mode |
| title_full | Monolayer molecular sensing using infrared leaky waveguide mode |
| title_fullStr | Monolayer molecular sensing using infrared leaky waveguide mode |
| title_full_unstemmed | Monolayer molecular sensing using infrared leaky waveguide mode |
| title_short | Monolayer molecular sensing using infrared leaky waveguide mode |
| title_sort | monolayer molecular sensing using infrared leaky waveguide mode |
| url | http://dx.doi.org/10.1063/5.0039597 |
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