Ultrasensitive circular dichroism spectroscopy based on coupled quasi-bound states in the continuum

Circular dichroism (CD) spectroscopy is essential for biochemistry, structural biology and pharmaceutical chemistry. While the chiroptical properties of chiral molecules are characterized by the Pasteur parameter κ, it is commonly conceived that the generation of CD is solely attributed to the imagi...

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Main Authors: Guan Tingting, Wang Zhenyu, Wang Ruize, Wu Zihan, Wang Chaowei, Wu Dong, Chu Jiaru, Chen Yang
Format: Article
Language:English
Published: De Gruyter 2025-01-01
Series:Nanophotonics
Subjects:
Online Access:https://doi.org/10.1515/nanoph-2024-0620
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author Guan Tingting
Wang Zhenyu
Wang Ruize
Wu Zihan
Wang Chaowei
Wu Dong
Chu Jiaru
Chen Yang
author_facet Guan Tingting
Wang Zhenyu
Wang Ruize
Wu Zihan
Wang Chaowei
Wu Dong
Chu Jiaru
Chen Yang
author_sort Guan Tingting
collection DOAJ
description Circular dichroism (CD) spectroscopy is essential for biochemistry, structural biology and pharmaceutical chemistry. While the chiroptical properties of chiral molecules are characterized by the Pasteur parameter κ, it is commonly conceived that the generation of CD is solely attributed to the imaginary part κ′′. However, since the imaginary part κ′′ is orders of magnitude smaller than the real part κ′ for most chiral molecules, the achievable sensitivity of CD spectroscopy is quite limited. Here, we report a recipe for realizing ultrasensitive CD spectroscopy based on the κ′ component of chiral molecules. Two quasi-bound states in the continuum are coupled by chiral molecules to form two hybridized branches, whose wavelengths and eigenpolarizations are very sensitive to the value of κ′. Giant CD signals over four orders of magnitude larger than the case without mode coupling are thus produced, paving the way towards chiral structure analysis at the single molecule level.
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institution OA Journals
issn 2192-8614
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publishDate 2025-01-01
publisher De Gruyter
record_format Article
series Nanophotonics
spelling doaj-art-78bd987cebea49fd92f7c5b4f575d1b22025-08-20T02:28:49ZengDe GruyterNanophotonics2192-86142025-01-011481083108910.1515/nanoph-2024-0620Ultrasensitive circular dichroism spectroscopy based on coupled quasi-bound states in the continuumGuan Tingting0Wang Zhenyu1Wang Ruize2Wu Zihan3Wang Chaowei4Wu Dong5Chu Jiaru6Chen Yang7Chinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, 12652University of Science and Technology of China, 230027Hefei, ChinaChinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, 12652University of Science and Technology of China, 230027Hefei, ChinaChinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, 12652University of Science and Technology of China, 230027Hefei, ChinaChinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, 12652University of Science and Technology of China, 230027Hefei, ChinaChinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, 12652University of Science and Technology of China, 230027Hefei, ChinaChinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, 12652University of Science and Technology of China, 230027Hefei, ChinaChinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, 12652University of Science and Technology of China, 230027Hefei, ChinaChinese Academy of Sciences Key Laboratory of Mechanical Behavior and Design of Materials, Department of Precision Machinery and Precision Instrumentation, 12652University of Science and Technology of China, 230027Hefei, ChinaCircular dichroism (CD) spectroscopy is essential for biochemistry, structural biology and pharmaceutical chemistry. While the chiroptical properties of chiral molecules are characterized by the Pasteur parameter κ, it is commonly conceived that the generation of CD is solely attributed to the imaginary part κ′′. However, since the imaginary part κ′′ is orders of magnitude smaller than the real part κ′ for most chiral molecules, the achievable sensitivity of CD spectroscopy is quite limited. Here, we report a recipe for realizing ultrasensitive CD spectroscopy based on the κ′ component of chiral molecules. Two quasi-bound states in the continuum are coupled by chiral molecules to form two hybridized branches, whose wavelengths and eigenpolarizations are very sensitive to the value of κ′. Giant CD signals over four orders of magnitude larger than the case without mode coupling are thus produced, paving the way towards chiral structure analysis at the single molecule level.https://doi.org/10.1515/nanoph-2024-0620cd spectroscopychiral sensingmode couplingbound state in the continuum
spellingShingle Guan Tingting
Wang Zhenyu
Wang Ruize
Wu Zihan
Wang Chaowei
Wu Dong
Chu Jiaru
Chen Yang
Ultrasensitive circular dichroism spectroscopy based on coupled quasi-bound states in the continuum
Nanophotonics
cd spectroscopy
chiral sensing
mode coupling
bound state in the continuum
title Ultrasensitive circular dichroism spectroscopy based on coupled quasi-bound states in the continuum
title_full Ultrasensitive circular dichroism spectroscopy based on coupled quasi-bound states in the continuum
title_fullStr Ultrasensitive circular dichroism spectroscopy based on coupled quasi-bound states in the continuum
title_full_unstemmed Ultrasensitive circular dichroism spectroscopy based on coupled quasi-bound states in the continuum
title_short Ultrasensitive circular dichroism spectroscopy based on coupled quasi-bound states in the continuum
title_sort ultrasensitive circular dichroism spectroscopy based on coupled quasi bound states in the continuum
topic cd spectroscopy
chiral sensing
mode coupling
bound state in the continuum
url https://doi.org/10.1515/nanoph-2024-0620
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