1
|
Biswas A, Cencillo-Abad P, Shabbir MW, Karmakar M, Chanda D. Tunable plasmonic superchiral light for ultrasensitive detection of chiral molecules. SCIENCE ADVANCES 2024; 10:eadk2560. [PMID: 38394206 PMCID: PMC10889367 DOI: 10.1126/sciadv.adk2560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 01/22/2024] [Indexed: 02/25/2024]
Abstract
The accurate detection, classification, and separation of chiral molecules are pivotal for advancing pharmaceutical and biomolecular innovations. Engineered chiral light presents a promising avenue to enhance the interaction between light and matter, offering a noninvasive, high-resolution, and cost-effective method for distinguishing enantiomers. Here, we present a nanostructured platform for surface-enhanced infrared absorption-induced vibrational circular dichroism (VCD) based on an achiral plasmonic system. This platform enables precise measurement, differentiation, and quantification of enantiomeric mixtures, including concentration and enantiomeric excess determination. Our experimental results exhibit a 13 orders of magnitude higher detection sensitivity for chiral enantiomers compared to conventional VCD spectroscopic techniques, accounting for respective path lengths and concentrations. The tunable spectral characteristics of this achiral plasmonic system facilitate the detection of a diverse range of chiral compounds. The platform's simplicity, tunability, and exceptional sensitivity holds remarkable potential for enantiomer classification in drug design, pharmaceuticals, and biological applications.
Collapse
Affiliation(s)
- Aritra Biswas
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, FL 32826, USA
- CREOL, The College of Optics and Photonics, University of Central Florida, 4304 Scorpius St., Orlando, FL 32816, USA
| | - Pablo Cencillo-Abad
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, FL 32826, USA
| | - Muhammad W Shabbir
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, FL 32826, USA
| | - Manobina Karmakar
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, FL 32826, USA
| | - Debashis Chanda
- NanoScience Technology Center, University of Central Florida, 12424 Research Parkway Suite 400, Orlando, FL 32826, USA
- CREOL, The College of Optics and Photonics, University of Central Florida, 4304 Scorpius St., Orlando, FL 32816, USA
- Department of Physics, University of Central Florida, 4111 Libra Drive, Physical Sciences Bldg. 430, Orlando, FL 32816, USA
| |
Collapse
|
2
|
Koyroytsaltis-McQuire DJP, Kumar R, Javorfi T, Siligardi G, Gadegaard N, Kadodwala M. Tuning dipolar and multipolar resonances of chiral silicon nanostructures for control of near field superchirality. NANOSCALE 2023; 16:110-122. [PMID: 38063462 DOI: 10.1039/d3nr05285k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Chiral materials display a property called optical activity, which is the capability to interact differentially with left and right circularly polarised light. This leads to the ability to manipulate the polarisation state of light, which has a broad range of applications spanning from energy efficient displays to quantum technologies. Both synthesised and engineered chiral nanomaterials are exploited in such devices. The design strategy for optimising the optical activity of a chiral material is typically based on maximising a single parameter, the electric dipole-magnetic dipole response. Here we demonstrate an alternative approach of controlling optical activity by manipulating both the dipole and multipolar response of a nanomaterial. This provides an additional parameter for material design, affording greater flexibility. The exemplar systems used to illustrate the strategy are nanofabricated chiral silicon structures. The multipolar response of the structures, and hence their optical activity, can be controlled simply by varying their height. This phenomenon allows optical activity and the creation of so called superchiral fields, with enhanced asymmetries, to be controlled over a broader wavelength range, than is achievable with just the electric dipole-magnetic dipole response. This work adds to the material design toolbox providing a route to novel nanomaterials for optoelectronics and sensing applications.
Collapse
Affiliation(s)
| | - Rahul Kumar
- School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Tamas Javorfi
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, UK
| | - Giuliano Siligardi
- Diamond Light Source Ltd, Harwell Science and Innovation Campus, Didcot, UK
| | - Nikolaj Gadegaard
- School of Engineering, Rankine Building, University of Glasgow, Glasgow G12 8LT, UK
| | | |
Collapse
|
3
|
Mohammadi E, Raziman TV, Curto AG. Nanophotonic Chirality Transfer to Dielectric Mie Resonators. NANO LETTERS 2023; 23:3978-3984. [PMID: 37126640 PMCID: PMC10176573 DOI: 10.1021/acs.nanolett.3c00739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Nanophotonics can boost the weak circular dichroism of chiral molecules. One mechanism for enhanced chiral sensing relies on using a resonator to create fields with high optical chirality at the molecular position. Here, we elucidate how the reverse interaction between molecules and the resonator, called chirality transfer, can produce stronger circular dichroism. The chiral analyte modifies the electric and magnetic dipole moments of the resonator, imprinting a chiral response on an otherwise achiral resonance. We demonstrate that silicon nanoparticles and metasurfaces tailored for chirality transfer generate chiroptical signals orders of magnitude higher than the contribution from optical chirality alone. We derive closed-form equations for the dependence of chirality transfer on molecular chirality, molecule-resonator distance, and Mie coefficients. We propose a dielectric metasurface for a 900-fold circular dichroism enhancement on the basis of these principles. Finally, we identify a fundamental limit to chirality transfer. Our findings thus establish key concepts for nanophotonic chiral sensing.
Collapse
Affiliation(s)
- Ershad Mohammadi
- Department of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
| | - T V Raziman
- Department of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
| | - Alberto G Curto
- Department of Applied Physics and Eindhoven Hendrik Casimir Institute, Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
- Photonics Research Group, Ghent University-imec, 9052 Ghent, Belgium
- Center for Nano- and Biophotonics, Ghent University, 9052 Ghent, Belgium
| |
Collapse
|
4
|
Guselnikova O, Elashnikov R, Svorcik V, Kartau M, Gilroy C, Gadegaard N, Kadodwala M, Karimullah AS, Lyutakov O. Coupling of plasmonic hot spots with shurikens for superchiral SERS-based enantiomer recognition. NANOSCALE HORIZONS 2023; 8:499-508. [PMID: 36752733 DOI: 10.1039/d3nh00008g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Detection of enantiomers is a challenging problem in drug development as well as environmental and food quality monitoring where traditional optical detection methods suffer from low signals and sensitivity. Application of surface enhanced Raman scattering (SERS) for enantiomeric discrimination is a powerful approach for the analysis of optically active small organic or large biomolecules. In this work, we proposed the coupling of disposable chiral plasmonic shurikens supporting the chiral near-field distribution with SERS active silver nanoclusters for enantio-selective sensing. As a result of the plasmonic coupling, significant difference in SERS response of optically active analytes is observed. The observations are studied by numerical simulations and it is hypothesized that the silver particles are being excited by superchiral fields generated at the surface inducing additional polarizations in the probe molecules. The plasmon coupling phenomena was found to be extremely sensitive to slight variations in shuriken geometry, silver nanostructured layer parameters, and SERS excitation wavelength(s). Designed structures were able to discriminate cysteine enantiomers at concentrations in the nanomolar range and probe biomolecular chirality, using a common Raman spectrometer within several minutes. The combination of disposable plasmonic substrates with specific near-field polarization can make the SERS enantiomer discrimination a commonly available technique using standard Raman spectrometers.
Collapse
Affiliation(s)
- Olga Guselnikova
- Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague, Czech Republic.
- Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, Tomsk, 634050, Russian Federation.
| | - Roman Elashnikov
- Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague, Czech Republic.
| | - Vaclav Svorcik
- Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague, Czech Republic.
| | - Martin Kartau
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Cameron Gilroy
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Nikolaj Gadegaard
- James Watt School of Engineering, University of Glasgow, Rankine Building, Glasgow, G12 8LT, UK
| | - Malcolm Kadodwala
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Affar S Karimullah
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Oleksiy Lyutakov
- Department of Solid State Engineering, University of Chemistry and Technology, 16628 Prague, Czech Republic.
| |
Collapse
|
5
|
Fahad AK, Ruan C, Nazir R, Hassan B. Transmissive Polarizer Metasurfaces: From Microwave to Optical Regimes. NANOMATERIALS 2022; 12:nano12101705. [PMID: 35630935 PMCID: PMC9144959 DOI: 10.3390/nano12101705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/06/2022] [Accepted: 05/12/2022] [Indexed: 11/16/2022]
Abstract
Metasurfaces, a special class of metamaterials, have recently become a rapidly growing field, particularly for thin polarization converters. They can be fabricated using a simple fabrication process due to their smaller planar profile, both in the microwave and optical regimes. In this paper, the recent progress in MSs for linear polarization (LP) to circular polarization (CP) conversion in transmission mode is reviewed. Starting from history, modeling and the theory of MSs, uncontrollable single and multiple bands and LP-to-CP conversions, are discussed and analyzed. Moreover, detailed reconfigurable MS-based LP-to-CP converters are presented. Further, key findings on the state-of-the-arts are discussed and tabulated to give readers a quick overview. Finally, a conclusion is drawn by providing opinions on future developments in this growing research field.
Collapse
Affiliation(s)
- Ayesha Kosar Fahad
- School of Electronics and Information Engineering, Beihang University, Beijing 100191, China;
| | - Cunjun Ruan
- School of Electronics and Information Engineering, Beihang University, Beijing 100191, China;
- Beijing Key Laboratory for Microwave Sensing and Security Applications, Beihang University, Beijing 100191, China
- Correspondence:
| | - Rabia Nazir
- Faculty of Electrical Engineering, University of Engineering and Technology, Lahore 100191, Pakistan;
| | - Bilal Hassan
- Department of Electrical Engineering and Computer Science, Khalifa University of Science and Technology, Abu Dhabi 127788, United Arab Emirates;
| |
Collapse
|
6
|
Zhao H, Xu Z, Lin J. Hierarchically Chiral Nanostructures Self-Assembled from Nanoparticle Tethered Block Copolymers. Macromol Rapid Commun 2022; 43:e2100855. [PMID: 35247288 DOI: 10.1002/marc.202100855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/29/2022] [Indexed: 11/07/2022]
Abstract
Chiral nanostructures of nanoparticle assemblies have attracted tremendous interest for their fascinating functional properties. Herein, through theoretical simulations, we show that nanoparticle tethered block copolymers can self-assemble into hierarchically chiral nanostructures. Two-fold helices are formed in the hierarchically chiral nanostructures: the diblock copolymers form helical supercylinders while the nanoparticles arrange into chiral assemblies wrapped around the helical supercylinders. The hierarchically chiral nanostructures can be formed in a large parameter window. Circular dichroism calculations demonstrate that the coexistence of polymeric helices and chiral nanoparticle assemblies improves the chiroptical activity. These findings can provide guidelines for designing hierarchically ordered chiral nanostructures with advanced functional properties. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Hongmeng Zhao
- Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Zhanwen Xu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Jiaping Lin
- Shanghai Key Laboratory of Advanced Polymeric Materials, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, 200237, China
| |
Collapse
|
7
|
Both S, Schäferling M, Sterl F, Muljarov EA, Giessen H, Weiss T. Nanophotonic Chiral Sensing: How Does It Actually Work? ACS NANO 2022; 16:2822-2832. [PMID: 35080371 DOI: 10.1021/acsnano.1c09796] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Nanophotonic chiral sensing has recently attracted a lot of attention. The idea is to exploit the strong light-matter interaction in nanophotonic resonators to determine the concentration of chiral molecules at ultralow thresholds, which is highly attractive for numerous applications in life science and chemistry. However, a thorough understanding of the underlying interactions is still missing. The theoretical description relies on either simple approximations or on purely numerical approaches. We close this gap and present a general theory of chiral light-matter interactions in arbitrary resonators. Our theory describes the chiral interaction as a perturbation of the resonator modes, also known as resonant states or quasi-normal modes. We observe two dominant contributions: A chirality-induced resonance shift and changes in the modes' excitation and emission efficiencies. Our theory brings deep insights for tailoring and enhancing chiral light-matter interactions. Furthermore, it allows us to predict spectra much more efficiently in comparison to conventional approaches. This is particularly true, as chiral interactions are inherently weak and therefore perturbation theory fits extremely well for this problem.
Collapse
Affiliation(s)
- Steffen Both
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Martin Schäferling
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Florian Sterl
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Egor A Muljarov
- Cardiff University, School of Physics and Astronomy, The Parade, CF24 3AA, Cardiff, United Kingdom
| | - Harald Giessen
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Thomas Weiss
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
- Institute of Physics, University of Graz, and NAWI Graz, Universitätsplatz 5, 8010 Graz, Austria
| |
Collapse
|
8
|
Hajji M, Cariello M, Gilroy C, Kartau M, Syme CD, Karimullah A, Gadegaard N, Malfait A, Woisel P, Cooke G, Peveler WJ, Kadodwala M. Chiral Quantum Metamaterial for Hypersensitive Biomolecule Detection. ACS NANO 2021; 15:19905-19916. [PMID: 34846858 DOI: 10.1021/acsnano.1c07408] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Chiral biological and pharmaceutical molecules are analyzed with phenomena that monitor their very weak differential interaction with circularly polarized light. This inherent weakness results in detection levels for chiral molecules that are inferior, by at least six orders of magnitude, to the single molecule level achieved by state-of-the-art chirally insensitive spectroscopic measurements. Here, we show a phenomenon based on chiral quantum metamaterials (CQMs) that overcomes these intrinsic limits. Specifically, the emission from a quantum emitter, a semiconductor quantum dot (QD), selectively placed in a chiral nanocavity is strongly perturbed when individual biomolecules (here, antibodies) are introduced into the cavity. The effect is extremely sensitive, with six molecules per nanocavity being easily detected. The phenomenon is attributed to the CQM being responsive to significant local changes in the optical density of states caused by the introduction of the biomolecule into the cavity. These local changes in the metamaterial electromagnetic environment, and hence the biomolecules, are invisible to "classical" light-scattering-based measurements. Given the extremely large effects reported, our work presages next generation technologies for rapid hypersensitive measurements with applications in nanometrology and biodetection.
Collapse
Affiliation(s)
- Maryam Hajji
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Michele Cariello
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Cameron Gilroy
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Martin Kartau
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Christopher D Syme
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Affar Karimullah
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Nikolaj Gadegaard
- School of Engineering, Rankine Building, University of Glasgow, Glasgow G12 8LT, United Kingdom
| | - Aurélie Malfait
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, F-59000 Lille, France
| | - Patrice Woisel
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, F-59000 Lille, France
| | - Graeme Cooke
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - William J Peveler
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Malcolm Kadodwala
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| |
Collapse
|
9
|
Spaeth P, Adhikari S, Baaske MD, Pud S, Ton J, Orrit M. Photothermal Circular Dichroism of Single Nanoparticles Rejecting Linear Dichroism by Dual Modulation. ACS NANO 2021; 15:16277-16285. [PMID: 34550678 PMCID: PMC8552490 DOI: 10.1021/acsnano.1c05374] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Circular dichroism (CD) is the property of chiral nanoobjects to absorb circularly polarized light of either handedness to different extents. Photothermal microscopy enables the detection of CD signals with high sensitivity and provides a direct absorptive response of the samples under study. To achieve CD measurements at the single-particle level, one must reduce such artifacts as leakage of linear dichroism (LD) and residual intensity modulation. We have simulated our setup with a simple model, which allows us to tune modulation parameters to obtain a CD signal virtually free from artifacts. We demonstrate the sensitivity of our setup by measuring the very weak inherent CD signals of single gold nanospheres. We furthermore demonstrate that our method can be extended to obtain spectra of the full absorptive properties of single nanoparticles, including isotropic absorption, linear dichroism, and circular dichroism. We then investigate nominally achiral gold nanoparticles immersed in a chiral liquid. Carefully taking into account the intrinsic chirality of the particles and its change due to heat-induced reshaping, we find that the chiral liquid carvone surrounding the particle has no measurable effect on the particles' chirality, down to g-factors of 3 × 10-4.
Collapse
Affiliation(s)
- Patrick Spaeth
- Huygens-Kamerlingh
Onnes Laboratory, Leiden University, Leiden, 2300 Rapenburg, Netherlands
| | - Subhasis Adhikari
- Huygens-Kamerlingh
Onnes Laboratory, Leiden University, Leiden, 2300 Rapenburg, Netherlands
| | - Martin Dieter Baaske
- Huygens-Kamerlingh
Onnes Laboratory, Leiden University, Leiden, 2300 Rapenburg, Netherlands
| | - Sergii Pud
- Huygens-Kamerlingh
Onnes Laboratory, Leiden University, Leiden, 2300 Rapenburg, Netherlands
| | - Jacco Ton
- Huygens-Kamerlingh
Onnes Laboratory, Leiden University, Leiden, 2300 Rapenburg, Netherlands
| | - Michel Orrit
- Huygens-Kamerlingh
Onnes Laboratory, Leiden University, Leiden, 2300 Rapenburg, Netherlands
| |
Collapse
|
10
|
Oshikiri T, Sun Q, Yamada H, Zu S, Sasaki K, Misawa H. Extrinsic Chirality by Interference between Two Plasmonic Modes on an Achiral Rectangular Nanostructure. ACS NANO 2021; 15:16802-16810. [PMID: 34582163 DOI: 10.1021/acsnano.1c07137] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The optical near field (NF) induced by circularly polarized light (CPL) is a hot scientific topic. We observed a chiral NF intensity distribution on a series of achiral gold nanorectangular structures (Au-NRs) under CPL irradiation by using multiphoton photoemission electron microscopy (MP-PEEM). Additionally, the differential NF spectra under left and right CPL irradiation, which represent the asymmetry of the NF intensity distribution, were investigated. We propose an interpretation that the chiral NF intensity distribution on an achiral metallic nanostructure is extrinsically generated by the interference between two plasmonic modes by combining state-of-the-art MP-PEEM techniques and the classical oscillator model. Our interpretation well explains both the experimental and simulation results. Furthermore, the intensity of the NF and its phase angle of each mode under linearly polarized light irradiation were revealed to be critical factors for the generation of extrinsic chirality in the NF intensity distribution.
Collapse
Affiliation(s)
- Tomoya Oshikiri
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Quan Sun
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Hiroki Yamada
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Shuai Zu
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Keiji Sasaki
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Hiroaki Misawa
- Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan
- Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 30010, Taiwan
| |
Collapse
|
11
|
Mohammadi E, Tittl A, Tsakmakidis KL, Raziman TV, Curto AG. Dual Nanoresonators for Ultrasensitive Chiral Detection. ACS PHOTONICS 2021; 8:1754-1762. [PMID: 34164565 PMCID: PMC8213055 DOI: 10.1021/acsphotonics.1c00311] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Indexed: 05/19/2023]
Abstract
The discrimination of enantiomers is crucial in biochemistry. However, chiral sensing faces significant limitations due to inherently weak chiroptical signals. Nanophotonics is a promising solution to enhance sensitivity thanks to increased optical chirality maximized by strong electric and magnetic fields. Metallic and dielectric nanoparticles can separately provide electric and magnetic resonances. Here we propose their synergistic combination in hybrid metal-dielectric nanostructures to exploit their dual character for superchiral fields beyond the limits of single particles. For optimal optical chirality, in addition to maximization of the resonance strength, the resonances must spectrally coincide. Simultaneously, their electric and magnetic fields must be parallel and π/2 out of phase and spatially overlap. We demonstrate that the interplay between the strength of the resonances and these optimal conditions constrains the attainable optical chirality in resonant systems. Starting from a simple symmetric nanodimer, we derive closed-form expressions elucidating its fundamental limits of optical chirality. Building on the trade-offs of different classes of dimers, we then suggest an asymmetric dual dimer based on realistic materials. These dual nanoresonators provide strong and decoupled electric and magnetic resonances together with optimal conditions for chiral fields. Finally, we introduce more complex dual building blocks for a metasurface with a record 300-fold enhancement of local optical chirality in nanoscale gaps, enabling circular dichroism enhancement by a factor of 20. By combining analytical insight and practical designs, our results put forward hybrid resonators to increase chiral sensitivity, particularly for small molecular quantities.
Collapse
Affiliation(s)
- Ershad Mohammadi
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Andreas Tittl
- Chair
in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539 Munich, Germany
| | - Kosmas L. Tsakmakidis
- Section
of Condensed Matter Physics, Department of Physics, National and Kapodistrian University of Athens, Panepistimioupolis, GR-157 84 Athens, Greece
| | - T. V. Raziman
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Alberto G. Curto
- Department
of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| |
Collapse
|
12
|
Lin ZH, Zhang J, Huang JS. Plasmonic elliptical nanoholes for chiroptical analysis and enantioselective optical trapping. NANOSCALE 2021; 13:9185-9192. [PMID: 33960333 DOI: 10.1039/d0nr09080h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A simple yet effective achiral platform using elliptical nanoholes for chiroptical analysis is demonstrated. Under linearly polarized excitation, an elliptical nanohole in a thin gold film can generate a localized chiral optical field for chiroptical analysis and simultaneously serve as a near-field optical trap to capture dielectric and plasmonic nanospheres. In particular, the trapping potential is enantioselective for dielectric nanospheres, i.e., the hole traps or repels the dielectric nanoparticles depending on the sample chirality. For plasmonic nanospheres, the trapping potential well is much deeper than that for dielectric particles, rendering the enantioselectivity less pronounced. This platform is suitable for chiral analysis with nanoparticle-based solid-state extraction and pre-concentration. Compared to plasmonic chiroptical sensing using chiral structures or circularly polarized light, elliptical nanoholes are a simple and effective platform, which is expected to have a relatively low background because chiroptical noise from the structure or chiral species outside the nanohole is minimized. The use of linearly polarized excitation also makes the platform easily compatible with a commercial optical microscope.
Collapse
Affiliation(s)
- Zhan-Hong Lin
- Leibniz Institute of Photonic Technology, Albert-Einstein Straße 9, 07745 Jena, Germany.
| | - Jiwei Zhang
- Leibniz Institute of Photonic Technology, Albert-Einstein Straße 9, 07745 Jena, Germany. and MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions, and Shaanxi Key Laboratory of Optical Information Technology, School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an 710129, China
| | - Jer-Shing Huang
- Leibniz Institute of Photonic Technology, Albert-Einstein Straße 9, 07745 Jena, Germany. and Abbe Center of Photonics, Friedrich-Schiller University Jena, Jena, Germany and Research Center for Applied Sciences, Academia Sinica, 128 Sec. 2, Academia Road, 11529 Taipei, Nankang District, Taiwan and Department of Electrophysics, National Chiao Tung University, 1001 University Road, 30010 Hsinchu, Taiwan
| |
Collapse
|
13
|
Chiral Dielectric Metasurfaces for Highly Integrated, Broadband Circularly Polarized Antenna. SENSORS 2021; 21:s21062071. [PMID: 33809458 PMCID: PMC8000959 DOI: 10.3390/s21062071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/10/2021] [Accepted: 03/10/2021] [Indexed: 11/17/2022]
Abstract
We report on the design of a low-profile integrated millimeter-wave antenna for efficient and broadband circularly polarized electromagnetic radiation. The designed antenna comprises a chiral dielectric metasurface built with a 2×2 arrangement of dielectric cylinders with slanted-slots at the center. A broadbeam high-gain with wide axial ratio (AR)<3 dB bandwidth was reached by pairing the electric and magnetic resonances of the dielectric cylinders and the slanted slots when excited by an elliptically polarized driven-patch antenna. This electric-magnetic pairing can be tuned by varying the cylinders diameter and the tilting and rotation angles of the slanted slots. The simulation results indicate impedance-matching bandwidths up to 22.6% (25.3-31.6 GHz) with 3-dB AR bandwidths of 11.6% (26.9-30.2 GHz), which in terms of compactness (0.95λ0×0.95λ0) and performance are superior to previous antenna designs. Since the simulations were performed by assuming materials and geometries easily implementable experimentally, it is hoped that circularly polarized antennas based on chiral metasurfaces can be integrated into 5G and satellite communications.
Collapse
|
14
|
Li J, Wang M, Wu Z, Li H, Hu G, Jiang T, Guo J, Liu Y, Yao K, Chen Z, Fang J, Fan D, Korgel BA, Alù A, Zheng Y. Tunable Chiral Optics in All-Solid-Phase Reconfigurable Dielectric Nanostructures. NANO LETTERS 2021; 21:973-979. [PMID: 33372805 PMCID: PMC7855985 DOI: 10.1021/acs.nanolett.0c03957] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Subwavelength nanostructures with tunable compositions and geometries show favorable optical functionalities for the implementation of nanophotonic systems. Precise and versatile control of structural configurations on solid substrates is essential for their applications in on-chip devices. Here, we report all-solid-phase reconfigurable chiral nanostructures with silicon nanoparticles and nanowires as the building blocks in which the configuration and chiroptical response can be tailored on-demand by dynamic manipulation of the silicon nanoparticle. We reveal that the optical chirality originates from the handedness-dependent coupling between optical resonances of the silicon nanoparticle and the silicon nanowire via numerical simulations and coupled-mode theory analysis. Furthermore, the coexisting electric and magnetic resonances support strong enhancement of optical near-field chirality, which enables label-free enantiodiscrimination of biomolecules in single nanostructures. Our results not only provide insight into the design of functional high-index materials but also bring new strategies to develop adaptive devices for photonic and electronic applications.
Collapse
Affiliation(s)
- Jingang Li
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Mingsong Wang
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Photonics Initiative, Advanced Science Research Center and Graduate Center, City University of New York, New York, New York 10075, United States
| | - Zilong Wu
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Huanan Li
- Photonics Initiative, Advanced Science Research Center and Graduate Center, City University of New York, New York, New York 10075, United States
| | - Guangwei Hu
- Photonics Initiative, Advanced Science Research Center and Graduate Center, City University of New York, New York, New York 10075, United States
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Taizhi Jiang
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jianhe Guo
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Yaoran Liu
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Kan Yao
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Zhihan Chen
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jie Fang
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Donglei Fan
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Brian A Korgel
- McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Andrea Alù
- Photonics Initiative, Advanced Science Research Center and Graduate Center, City University of New York, New York, New York 10075, United States
| | - Yuebing Zheng
- Materials Science and Engineering Program, Texas Materials Institute, and Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
| |
Collapse
|
15
|
Kakkar T, Keijzer C, Rodier M, Bukharova T, Taliansky M, Love AJ, Milner JJ, Karimullah AS, Barron LD, Gadegaard N, Lapthorn AJ, Kadodwala M. Superchiral near fields detect virus structure. LIGHT, SCIENCE & APPLICATIONS 2020; 9:195. [PMID: 33298854 PMCID: PMC7705013 DOI: 10.1038/s41377-020-00433-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/28/2020] [Accepted: 11/11/2020] [Indexed: 05/14/2023]
Abstract
Optical spectroscopy can be used to quickly characterise the structural properties of individual molecules. However, it cannot be applied to biological assemblies because light is generally blind to the spatial distribution of the component molecules. This insensitivity arises from the mismatch in length scales between the assemblies (a few tens of nm) and the wavelength of light required to excite chromophores (≥150 nm). Consequently, with conventional spectroscopy, ordered assemblies, such as the icosahedral capsids of viruses, appear to be indistinguishable isotropic spherical objects. This limits potential routes to rapid high-throughput portable detection appropriate for point-of-care diagnostics. Here, we demonstrate that chiral electromagnetic (EM) near fields, which have both enhanced chiral asymmetry (referred to as superchirality) and subwavelength spatial localisation (∼10 nm), can detect the icosahedral structure of virus capsids. Thus, they can detect both the presence and relative orientation of a bound virus capsid. To illustrate the potential uses of the exquisite structural sensitivity of subwavelength superchiral fields, we have used them to successfully detect virus particles in the complex milieu of blood serum.
Collapse
Affiliation(s)
- Tarun Kakkar
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
| | - Chantal Keijzer
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
- Institute of Molecular, Cell and Systems Biology and School of Life Sciences, University of Glasgow, G12 8QQ, Glasgow, UK.
| | - Marion Rodier
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | | | - Michael Taliansky
- James Hutton Inst, Cell & Mol Sci, Dundee, DD2 5DA, UK
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, 117997, Russia
| | - Andrew J Love
- James Hutton Inst, Cell & Mol Sci, Dundee, DD2 5DA, UK
| | - Joel J Milner
- Institute of Molecular, Cell and Systems Biology and School of Life Sciences, University of Glasgow, G12 8QQ, Glasgow, UK
| | - Affar S Karimullah
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Laurence D Barron
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Nikolaj Gadegaard
- School of Engineering, Rankine Building, University of Glasgow, Glasgow, G12 8LT, UK
| | - Adrian J Lapthorn
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Malcolm Kadodwala
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK.
| |
Collapse
|
16
|
Armelles G, Bergamini L, Cebollada A, González MU, Álvaro R, Torné L, Zabala N, Aizpurua J. Magnetic modulation of far- and near-field IR properties in rod-slit complementary spintronic metasurfaces. OPTICS EXPRESS 2020; 28:32584-32600. [PMID: 33114941 DOI: 10.1364/oe.404046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 10/01/2020] [Indexed: 06/11/2023]
Abstract
Complementary metasurfaces composed of randomly-placed arrays of aligned rods or slits are fabricated out of giant magnetoresistance Ni81Fe19/Au multilayers (MLs), a material whose optical properties change under the application of an external static magnetic field. The two metasurfaces are studied from both the experimental and theoretical viewpoints. The induced magnetic modulation (MM) of both the far-field signal and the resonant near field, at the rod/slit localized surface plasmon frequency, are found to obey the Babinet's principle. Furthermore, the near-field MM is found to be higher than the far-field counterpart. At resonance, both arrays show spots with high values of the magnetic modulated intensity of the electric near field (MM hot-spots). We show that this high magnetic modulation of the near-field intensity is very promising for the future development of high sensitivity molecular sensing platforms in the Mid- and Far-IR, using Magnetic-Modulation of Surface-Enhanced Infrared Absorption (MM-SEIRA) spectroscopy.
Collapse
|
17
|
Solomon ML, Abendroth JM, Poulikakos LV, Hu J, Dionne JA. Fluorescence-Detected Circular Dichroism of a Chiral Molecular Monolayer with Dielectric Metasurfaces. J Am Chem Soc 2020; 142:18304-18309. [PMID: 33048539 DOI: 10.1021/jacs.0c07140] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Strong enhancement of molecular circular dichroism (CD) has the potential to enable efficient asymmetric photolysis, a method of chiral separation that has conventionally been impeded by insufficient yield and low enantiomeric excess. Here, we study experimentally how predicted enhancements in optical chirality density near resonant silicon nanodisks boost CD. We use fluorescence-detected circular dichroism (FDCD) spectroscopy to measure indirectly the differential absorption of circularly polarized light by a monolayer of optically active molecules functionalized to silicon nanodisk arrays. Importantly, the molecules and nanodisk antennas have spectrally coincident resonances, and our fluorescence technique allows us to deconvolute absorption in the nanodisks from the molecules. We find that enhanced FDCD signals depend on nanophotonic resonances, in good agreement with simulated differential absorption and optical chirality density, while no signal is detected from molecules adsorbed on featureless silicon surfaces. These results verify the potential of nanophotonic platforms to be used for asymmetric photolysis with lower energy requirements.
Collapse
Affiliation(s)
- Michelle L Solomon
- Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, United States
| | - John M Abendroth
- Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, United States
| | - Lisa V Poulikakos
- Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, United States.,Mechanical and Aerospace Engineering, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, United States
| | - Jack Hu
- Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, United States
| | - Jennifer A Dionne
- Materials Science and Engineering, Stanford University, 496 Lomita Mall, Stanford, California 94305, United States
| |
Collapse
|
18
|
Mun J, Kim M, Yang Y, Badloe T, Ni J, Chen Y, Qiu CW, Rho J. Electromagnetic chirality: from fundamentals to nontraditional chiroptical phenomena. LIGHT, SCIENCE & APPLICATIONS 2020; 9:139. [PMID: 32922765 PMCID: PMC7463035 DOI: 10.1038/s41377-020-00367-8] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 06/25/2020] [Accepted: 07/08/2020] [Indexed: 05/05/2023]
Abstract
Chirality arises universally across many different fields. Recent advancements in artificial nanomaterials have demonstrated chiroptical responses that far exceed those found in natural materials. Chiroptical phenomena are complicated processes that involve transitions between states with opposite parities, and solid interpretations of these observations are yet to be clearly provided. In this review, we present a comprehensive overview of the theoretical aspects of chirality in light, nanostructures, and nanosystems and their chiroptical interactions. Descriptions of observed chiroptical phenomena based on these fundamentals are intensively discussed. We start with the strong intrinsic and extrinsic chirality in plasmonic nanoparticle systems, followed by enantioselective sensing and optical manipulation, and then conclude with orbital angular momentum-dependent responses. This review will be helpful for understanding the mechanisms behind chiroptical phenomena based on underlying chiral properties and useful for interpreting chiroptical systems for further studies.
Collapse
Affiliation(s)
- Jungho Mun
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Minkyung Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Younghwan Yang
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Trevon Badloe
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| | - Jincheng Ni
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583 Singapore
| | - Yang Chen
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583 Singapore
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117583 Singapore
| | - Junsuk Rho
- Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
- Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673 Korea
| |
Collapse
|
19
|
Abstract
Optical polarization features associated with the fundamental processes of molecular fluorescence and resonance energy transfer are in general studied with reference to plane polarizations. When any of the species involved is chiral, the associated emission processes may exhibit an element of circular polarization-a degree of optical helicity. Although usually a minor effect, some systems can exhibit a sizeable component of circularly polarized luminescence, whose helicity correlates with the enantiomeric form. In studies of multi-component systems, in which initial excitation of a donor species-followed by energy transfer-leads to emission from an acceptor molecule, the handedness of both donor and acceptor may influence output circularity. In systems with an achiral acceptor, a degree of fluorescence circularity may be influenced by the handedness of a chiral donor, but this should not be construed in terms of 'conveying' chirality. Chiral molecules may also play a passive role by inducing helicity in the fluorescence from achiral neighbours, and further tiers of complexity arise if the initial excitation is itself of circular polarization. In all such processes, symmetry principles play a major role in determining a sensitivity to molecular handedness, and their detailed consideration enables a range of new experimental procedures to be identified. Casting the fundamental theory in terms of formal photon-molecule couplings enables the quantum mechanisms involved in all such phenomena to be clearly resolved. The results provide fresh physical insights, and establish connections across a range of indirectly related chiroptical phenomena including induced circular dichroism.
Collapse
Affiliation(s)
- David L Andrews
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| |
Collapse
|
20
|
Bochenkov VE, Shabatina TI. Chiral Plasmonic Biosensors. BIOSENSORS 2018; 8:E120. [PMID: 30513775 PMCID: PMC6316110 DOI: 10.3390/bios8040120] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/25/2018] [Accepted: 11/29/2018] [Indexed: 12/17/2022]
Abstract
Biosensing requires fast, selective, and highly sensitive real-time detection of biomolecules using efficient simple-to-use techniques. Due to a unique capability to focus light at nanoscale, plasmonic nanostructures provide an excellent platform for label-free detection of molecular adsorption by sensing tiny changes in the local refractive index or by enhancing the light-induced processes in adjacent biomolecules. This review discusses the opportunities provided by surface plasmon resonance in probing the chirality of biomolecules as well as their conformations and orientations. Various types of chiral plasmonic nanostructures and the most recent developments in the field of chiral plasmonics related to biosensing are considered.
Collapse
Affiliation(s)
- Vladimir E Bochenkov
- Chemistry Department of Lomonosov, Moscow State University, 119991 Moskva, Russia.
| | - Tatyana I Shabatina
- Chemistry Department of Lomonosov, Moscow State University, 119991 Moskva, Russia.
| |
Collapse
|
21
|
Xiao TH, Cheng Z, Goda K. Giant Optical Activity in an All-Dielectric Spiral Nanoflower. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1800485. [PMID: 29968281 DOI: 10.1002/smll.201800485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2018] [Revised: 05/25/2018] [Indexed: 06/08/2023]
Abstract
Optical activity is an effect of prominent importance in stereochemistry, analytical chemistry, metamaterials, spin photonics, and astrobiology, but is naturally minuscule. Metallic nanostructures are commonly exploited as basic elements for artificially producing large optical activity by virtue of surface plasmon resonance (SPR) on the nanostructures. However, their intrinsic high ohmic loss amplified by the SPR results in low energy efficiency and large photothermal heat generation, severely limiting their performance and practical utility. Giant optical activity by inducing magnetic resonance in an all-dielectric spiral nanoflower (spiral-flower-shaped nanostructure) is demonstrated here. Specifically, a large circular-intensity difference of ≈35% is theoretically predicted and experimentally demonstrated by optimizing the magnetic quadrupole contribution of the nanoflower to scattered light. The nanoflower overcomes the bottleneck of the traditional metallic platforms and enables the development of diverse chiroptical devices and applications.
Collapse
Affiliation(s)
- Ting-Hui Xiao
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
| | - Zhenzhou Cheng
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
| | - Keisuke Goda
- Department of Chemistry, University of Tokyo, Tokyo, 113-0033, Japan
- Department of Electrical Engineering, University of California, Los Angeles, CA, 90095, USA
| |
Collapse
|
22
|
Kelly C, Tullius R, Lapthorn AJ, Gadegaard N, Cooke G, Barron LD, Karimullah AS, Rotello VM, Kadodwala M. Chiral Plasmonic Fields Probe Structural Order of Biointerfaces. J Am Chem Soc 2018; 140:8509-8517. [PMID: 29909628 PMCID: PMC6070957 DOI: 10.1021/jacs.8b03634] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
![]()
The
structural order of biopolymers, such as proteins, at interfaces
defines the physical and chemical interactions of biological systems
with their surroundings and is hence a critical parameter in a range
of biological problems. Known spectroscopic methods for routine rapid
monitoring of structural order in biolayers are generally only applied
to model single-component systems that possess a spectral fingerprint
which is highly sensitive to orientation. This spectroscopic behavior
is not a generic property and may require the addition of a label.
Importantly, such techniques cannot readily be applied to real multicomponent
biolayers, have ill-defined or unknown compositions, and have complex
spectroscopic signatures with many overlapping bands. Here, we demonstrate
the sensitivity of plasmonic fields with enhanced chirality, a property
referred to as superchirality, to global orientational order within
both simple model and “real” complex protein layers.
The sensitivity to structural order is derived from the capability
of superchiral fields to detect the anisotropic nature of electric
dipole–magnetic dipole response of the layer; this is validated
by numerical simulations. As a model study, the evolution of orientational
order with increasing surface density in layers of the antibody immunoglobulin
G was monitored. As an exemplar of greater complexity, superchiral
fields are demonstrated, without knowledge of exact composition, to
be able to monitor how qualitative changes in composition alter the
structural order of protein layers formed from blood serum, thereby
establishing the efficacy of the phenomenon as a tool for studying
complex biological interfaces.
Collapse
Affiliation(s)
- Christopher Kelly
- School of Chemistry , Joseph Black Building, University of Glasgow , Glasgow G12 8QQ , United Kingdom
| | - Ryan Tullius
- School of Chemistry , Joseph Black Building, University of Glasgow , Glasgow G12 8QQ , United Kingdom
| | - Adrian J Lapthorn
- School of Chemistry , Joseph Black Building, University of Glasgow , Glasgow G12 8QQ , United Kingdom
| | - Nikolaj Gadegaard
- School of Engineering , Rankine Building, University of Glasgow , Glasgow G12 8LT , United Kingdom
| | - Graeme Cooke
- School of Chemistry , Joseph Black Building, University of Glasgow , Glasgow G12 8QQ , United Kingdom
| | - Laurence D Barron
- School of Chemistry , Joseph Black Building, University of Glasgow , Glasgow G12 8QQ , United Kingdom
| | - Affar S Karimullah
- School of Chemistry , Joseph Black Building, University of Glasgow , Glasgow G12 8QQ , United Kingdom.,School of Engineering , Rankine Building, University of Glasgow , Glasgow G12 8LT , United Kingdom
| | - Vincent M Rotello
- Department of Chemistry , University of Massachusetts , 710 N. Pleasant Street , Amherst , Massachusetts 01003 , United States
| | - Malcolm Kadodwala
- School of Chemistry , Joseph Black Building, University of Glasgow , Glasgow G12 8QQ , United Kingdom
| |
Collapse
|
23
|
Alpeggiani F, Bliokh KY, Nori F, Kuipers L. Electromagnetic Helicity in Complex Media. PHYSICAL REVIEW LETTERS 2018; 120:243605. [PMID: 29956970 DOI: 10.1103/physrevlett.120.243605] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Indexed: 06/08/2023]
Abstract
Optical helicity density is usually discussed for monochromatic electromagnetic fields in free space. It plays an important role in the interaction with chiral molecules or nanoparticles. Here we introduce the optical helicity density in a dispersive isotropic medium. Our definition is consistent with biorthogonal Maxwell electromagnetism in optical media and the Brillouin energy density as well as with the recently introduced canonical momentum and spin of light in dispersive media. We consider a number of examples, including electromagnetic waves in dielectrics, negative-index materials, and metals, as well as interactions of light in a medium with chiral and magnetoelectric molecules.
Collapse
Affiliation(s)
- F Alpeggiani
- Department of Quantum Nanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands
| | - K Y Bliokh
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
- Nonlinear Physics Centre, RSPE, The Australian National University, Canberra ACT 0200, Australia
| | - F Nori
- Theoretical Quantum Physics Laboratory, RIKEN Cluster for Pioneering Research, Wako-shi, Saitama 351-0198, Japan
- Physics Department, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
| | - L Kuipers
- Department of Quantum Nanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, Delft 2628 CJ, The Netherlands
| |
Collapse
|
24
|
Mun J, Rho J. Surface-enhanced circular dichroism by multipolar radiative coupling. OPTICS LETTERS 2018; 43:2856-2859. [PMID: 29905707 DOI: 10.1364/ol.43.002856] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/17/2018] [Indexed: 06/08/2023]
Abstract
We present numerical investigation of the mechanism of surface-enhanced circular dichroism of a chiral medium near nanoantennas. Strong circular dichroism was observed from the chiral medium surrounding nanoantennas with multipolar resonant modes, and the strong circular dichroism was more correlated to the multipolar resonances than to nearfield enhancement or optical helicity enhancement. According to this observation, we suggest multipolar radiative coupling between the nanoantennas and chiral medium as a possible mechanism of the strong chiral response. This work clarifies a mechanism of surface-enhanced chiral responses and would be useful for designing an enantiomeric-sensing platform and realizing devices relying on strong chirality, such as topological metamaterials for scattering-immune propagation of light and negative index metamaterials.
Collapse
|
25
|
Pellegrini G, Finazzi M, Celebrano M, Duò L, Biagioni P. Surface-enhanced chiroptical spectroscopy with superchiral surface waves. Chirality 2018; 30:883-889. [PMID: 29782670 DOI: 10.1002/chir.22971] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 11/06/2022]
Abstract
We study the chiroptical properties of one-dimensional photonic crystals supporting superchiral surface waves by introducing a simple formalism based on the Fresnel reflection matrix. We show that the proposed framework provides useful insights on the behavior of all the relevant chiroptical quantities, allowing for a deeper understanding of surface-enhanced chiral sensing platforms based on one-dimensional photonic crystals. Finally, we analyze and discuss the limitations of such platforms as the surface concentration of the target chiral analytes is gradually increased.
Collapse
Affiliation(s)
| | - Marco Finazzi
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | | | - Lamberto Duò
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Paolo Biagioni
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| |
Collapse
|
26
|
Vázquez-Guardado A, Chanda D. Superchiral Light Generation on Degenerate Achiral Surfaces. PHYSICAL REVIEW LETTERS 2018; 120:137601. [PMID: 29694216 DOI: 10.1103/physrevlett.120.137601] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Indexed: 05/12/2023]
Abstract
A novel route of superchiral near-field generation is demonstrated based on geometrically achiral systems supporting degenerate and spatially superimposed plasmonic modes. Such systems generate a single-handed chiral near field with simultaneous zero far-field circular dichroism. The phenomenon is theoretically elucidated with a rotating dipole model, which predicts a uniform single-handed chiral near field that flips handedness solely by reversing the handedness of the source. This property allows detection of pure background free molecular chirality through near-field light-matter interaction, which is experimentally demonstrated in the precise identification of both handedness of a chiral molecule on a single substrate with about four orders of magnitude enhancement in detection sensitivity compared to its conventional volumetric counterpart.
Collapse
Affiliation(s)
- Abraham Vázquez-Guardado
- CREOL, College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816, USA
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA
| | - Debashis Chanda
- CREOL, College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816, USA
- NanoScience Technology Center, University of Central Florida, Orlando, Florida 32826, USA
- Department of Physics, University of Central Florida, Orlando, Florida 32816, USA
| |
Collapse
|
27
|
Tullius R, Platt GW, Khorashad LK, Gadegaard N, Lapthorn AJ, Rotello VM, Cooke G, Barron LD, Govorov AO, Karimullah AS, Kadodwala M. Superchiral Plasmonic Phase Sensitivity for Fingerprinting of Protein Interface Structure. ACS NANO 2017; 11:12049-12056. [PMID: 29220155 PMCID: PMC6034627 DOI: 10.1021/acsnano.7b04698] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The structure adopted by biomaterials, such as proteins, at interfaces is a crucial parameter in a range of important biological problems. It is a critical property in defining the functionality of cell/bacterial membranes and biofilms (i.e., in antibiotic-resistant infections) and the exploitation of immobilized enzymes in biocatalysis. The intrinsically small quantities of materials at interfaces precludes the application of conventional spectroscopic phenomena routinely used for (bio)structural analysis due to a lack of sensitivity. We show that the interaction of proteins with superchiral fields induces asymmetric changes in retardation phase effects of excited bright and dark modes of a chiral plasmonic nanostructure. Phase retardations are obtained by a simple procedure, which involves fitting the line shape of resonances in the reflectance spectra. These interference effects provide fingerprints that are an incisive probe of the structure of interfacial biomolecules. Using these fingerprints, layers composed of structurally related proteins with differing geometries can be discriminated. Thus, we demonstrate a powerful tool for the bioanalytical toolbox.
Collapse
Affiliation(s)
- Ryan Tullius
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Geoffrey W. Platt
- Avacta Life Sciences, Ash Way, Thorp Arch Estate, Wetherby, LS23 7FA, UK
| | | | - Nikolaj Gadegaard
- School of Engineering, Rankine Building, University of Glasgow, Glasgow, G12 8LT, UK
| | - Adrian J. Lapthorn
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Vincent M. Rotello
- Department of Chemistry, 710 Nt. Pleasant Street, University of Massachusetts Amherst, MA 01003, USA
| | - Graeme Cooke
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Laurence D. Barron
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| | | | - Affar S. Karimullah
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
- School of Engineering, Rankine Building, University of Glasgow, Glasgow, G12 8LT, UK
| | - Malcolm Kadodwala
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ, UK
| |
Collapse
|
28
|
Proskurin I, Stamps RL, Ovchinnikov AS, Kishine JI. Spin-Wave Chirality and Its Manifestations in Antiferromagnets. PHYSICAL REVIEW LETTERS 2017; 119:177202. [PMID: 29219475 DOI: 10.1103/physrevlett.119.177202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Indexed: 06/07/2023]
Abstract
As first demonstrated by Tang and Cohen in chiral optics, the asymmetry in the rate of electromagnetic energy absorption between left and right enantiomers is determined by an optical chirality density. Here, we demonstrate that this effect can exist in magnetic spin systems. By constructing a formal analogy with electrodynamics, we show that in antiferromagnets with broken chiral symmetry, the asymmetry in local spin-wave energy absorption is proportional to a spin-wave chirality density, which is a direct counterpart of optical zilch. We propose that injection of a pure spin current into an antiferromagnet may serve as a chiral symmetry breaking mechanism, since its effect in the spin-wave approximation can be expressed in terms of additional Lifshitz invariants. We use linear response theory to show that the spin current induces a nonequilibrium spin-wave chirality density.
Collapse
Affiliation(s)
- Igor Proskurin
- Division of Natural and Environmental Sciences, The Open University of Japan, Chiba 261-8586, Japan
- Institute of Natural Sciences and Mathematics, Ural Federal University, Ekaterinburg 620002, Russia
| | - Robert L Stamps
- Department of Physics and Astronomy, University of Manitoba, Winnipeg MB R3T 2N2, Canada
| | - Alexander S Ovchinnikov
- Institute of Natural Sciences and Mathematics, Ural Federal University, Ekaterinburg 620002, Russia
- Institute for Metal Physics, RAS, Ekaterinburg 620137, Russia
| | - Jun-Ichiro Kishine
- Division of Natural and Environmental Sciences, The Open University of Japan, Chiba 261-8586, Japan
| |
Collapse
|
29
|
Wang X, Wang M, Lei R, Zhu SF, Zhao Y, Chen C. Chiral Surface of Nanoparticles Determines the Orientation of Adsorbed Transferrin and Its Interaction with Receptors. ACS NANO 2017; 11:4606-4616. [PMID: 28460159 DOI: 10.1021/acsnano.7b00200] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
When nanoparticles are exposed to a physiological environment, a "protein corona" is formed that greatly determines their biological fate. Adsorption of proteins could be influenced by chiral surfaces of nanoparticles; however, very few quantitative studies are available on the interaction of protein with the chiral surface of nanoparticles, and the underlying mechanism remains largely unresolved. We have developed a strategy to quantitatively analyze the adsorption and conformational features of transferrin on gold nanoparticles that are functionalized with d, l, and racemic penicillamine. We used a quartz microbalance platform to monitor the interaction of the adsorbed transferrin with transferrin receptors in HEK cell-derived liposomes. Results show that the chiral surface of nanoparticle determines the orientation and conformation of transferrin, which subsequently affects the interaction and recognition of transferrin with its receptor on the cellular membrane. Transferrin is widely used as a tumor-targeting ligand in cancer treatment and diagnosis since the transferrin receptor is overexpressed on the cell membrane of various types of cancer cells. Thus, the present results will help to expand the knowledge on biological identity of nanoparticles with chiral surfaces in a physiological environment and provide an insight into the rational design of therapeutic nanoparticles.
Collapse
Affiliation(s)
- Xinyi Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety and CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China and University of Chinese Academy of Sciences , Beijing 100190, China
- College of Science, Shenyang Agricultural University , Shenyang 110866, China
| | - Mingzhe Wang
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety and CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China and University of Chinese Academy of Sciences , Beijing 100190, China
| | - Rong Lei
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine , Beijing 100029, China
| | - Shui Fang Zhu
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine , Beijing 100029, China
| | - Yuliang Zhao
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety and CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China and University of Chinese Academy of Sciences , Beijing 100190, China
| | - Chunying Chen
- CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety and CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology of China and University of Chinese Academy of Sciences , Beijing 100190, China
| |
Collapse
|
30
|
Kramer C, Schäferling M, Weiss T, Giessen H, Brixner T. Analytic Optimization of Near-Field Optical Chirality Enhancement. ACS PHOTONICS 2017; 4:396-406. [PMID: 28239617 PMCID: PMC5319396 DOI: 10.1021/acsphotonics.6b00887] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Indexed: 05/10/2023]
Abstract
We present an analytic derivation for the enhancement of local optical chirality in the near field of plasmonic nanostructures by tuning the far-field polarization of external light. We illustrate the results by means of simulations with an achiral and a chiral nanostructure assembly and demonstrate that local optical chirality is significantly enhanced with respect to circular polarization in free space. The optimal external far-field polarizations are different from both circular and linear. Symmetry properties of the nanostructure can be exploited to determine whether the optimal far-field polarization is circular. Furthermore, the optimal far-field polarization depends on the frequency, which results in complex-shaped laser pulses for broadband optimization.
Collapse
Affiliation(s)
- Christian Kramer
- Institut
für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Martin Schäferling
- 4th
Physics Institute, Research Center SCoPE, and Research Center SimTech, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Thomas Weiss
- 4th
Physics Institute, Research Center SCoPE, and Research Center SimTech, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Harald Giessen
- 4th
Physics Institute, Research Center SCoPE, and Research Center SimTech, University of Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany
| | - Tobias Brixner
- Institut
für Physikalische und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
- E-mail:
| |
Collapse
|
31
|
Wang Z, Cheng F, Winsor T, Liu Y. Optical chiral metamaterials: a review of the fundamentals, fabrication methods and applications. NANOTECHNOLOGY 2016; 27:412001. [PMID: 27606801 DOI: 10.1088/0957-4484/27/41/412001] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Optical chiral metamaterials have recently attracted considerable attention because they offer new and exciting opportunities for fundamental research and practical applications. Through pragmatic designs, the chiroptical response of chiral metamaterials can be several orders of magnitude higher than that of natural chiral materials. Meanwhile, the local chiral fields can be enhanced by plasmonic resonances to drive a wide range of physical and chemical processes in both linear and nonlinear regimes. In this review, we will discuss the fundamental principles of chiral metamaterials, various optical chiral metamaterials realized by different nanofabrication approaches, and the applications and future prospects of this emerging field.
Collapse
Affiliation(s)
- Zuojia Wang
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115, USA
| | | | | | | |
Collapse
|
32
|
Jack C, Karimullah AS, Leyman R, Tullius R, Rotello VM, Cooke G, Gadegaard N, Barron LD, Kadodwala M. Biomacromolecular Stereostructure Mediates Mode Hybridization in Chiral Plasmonic Nanostructures. NANO LETTERS 2016; 16:5806-14. [PMID: 27547978 DOI: 10.1021/acs.nanolett.6b02549] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The refractive index sensitivity of plasmonic fields has been exploited for over 20 years in analytical technologies. While this sensitivity can be used to achieve attomole detection levels, they are in essence binary measurements that sense the presence/absence of a predetermined analyte. Using plasmonic fields, not to sense effective refractive indices but to provide more "granular" information about the structural characteristics of a medium, provides a more information rich output, which affords opportunities to create new powerful and flexible sensing technologies not limited by the need to synthesize chemical recognition elements. Here we report a new plasmonic phenomenon that is sensitive to the biomacromolecular structure without relying on measuring effective refractive indices. Chiral biomaterials mediate the hybridization of electric and magnetic modes of a chiral solid-inverse plasmonic structure, resulting in a measurable change in both reflectivity and chiroptical properties. The phenomenon originates from the electric-dipole-magnetic-dipole response of the biomaterial and is hence sensitive to biomacromolecular secondary structure providing unique fingerprints of α-helical, β-sheet, and disordered motifs. The phenomenon can be observed for subchiral plasmonic fields (i.e., fields with a lower chiral asymmetry than circularly polarized light) hence lifting constraints to engineer structures that produce fields with enhanced chirality, thus providing greater flexibility in nanostructure design. To demonstrate the efficacy of the phenomenon, we have detected and characterized picogram quantities of simple model helical biopolymers and more complex real proteins.
Collapse
Affiliation(s)
- Calum Jack
- School of Chemistry, Joseph Black Building, University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Affar S Karimullah
- School of Chemistry, Joseph Black Building, University of Glasgow , Glasgow G12 8QQ, United Kingdom
- School of Engineering, Rankine Building, University of Glasgow , Glasgow G12 8LT, United Kingdom
| | - Ross Leyman
- School of Chemistry, Joseph Black Building, University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Ryan Tullius
- School of Chemistry, Joseph Black Building, University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Vincent M Rotello
- Department of Chemistry, 710 N. Pleasant Street, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Graeme Cooke
- School of Chemistry, Joseph Black Building, University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Nikolaj Gadegaard
- School of Engineering, Rankine Building, University of Glasgow , Glasgow G12 8LT, United Kingdom
| | - Laurence D Barron
- School of Chemistry, Joseph Black Building, University of Glasgow , Glasgow G12 8QQ, United Kingdom
| | - Malcolm Kadodwala
- School of Chemistry, Joseph Black Building, University of Glasgow , Glasgow G12 8QQ, United Kingdom
| |
Collapse
|
33
|
Li G, Li Q, Yang L, Wu L. Optical magnetism and optical activity in nonchiral planar plasmonic metamaterials. OPTICS LETTERS 2016; 41:2911-2914. [PMID: 27367063 DOI: 10.1364/ol.41.002911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigate optical magnetism and optical activity in a simple planar metamolecule composed of double U-shaped metal split ring resonators (SRRs) twisted by 90° with respect to one another. Compared to a single SRR, the resonant energy levels are split and strong magnetic response can be observed due to inductive and conductive coupling. More interestingly, the nonchiral structures exhibit strong optical gyrotropy (1100°/λ) under oblique incidence, benefiting from the strong electromagnetic coupling. A chiral molecule model is proposed to shed light on the physical origin of optical activity. These artificial chiral metamaterials could be utilized to control the polarization of light and promise applications in enantiomer sensing-based medicine, biology, and drug development.
Collapse
|
34
|
Multipolar Effects in the Optical Active Second Harmonic Generation from Sawtooth Chiral Metamaterials. Sci Rep 2016; 6:22061. [PMID: 26911449 PMCID: PMC4766511 DOI: 10.1038/srep22061] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 02/04/2016] [Indexed: 11/08/2022] Open
Abstract
Based on the facts that chiral molecules response differently to left- and right-handed circular polarized light, chiroptical effects are widely employed for determining structure chirality, detecting enantiomeric excess, or controlling chemical reactions of molecules. Compared to those in natural materials, chiroptical behaviors can be significantly amplified in chiral plasmonic metamaterials due to the concentrated local fields in the structure. The on-going research towards giant chiroptical effects in metamaterial generally focus on optimizing the field-enhancement effects. However, the observed chiroptical effects in metamaterials rely on more complicated factors and various possibilities towards giant chiroptical effects remains unexplored. Here we study the optical-active second harmonic generation (SHG) behaviors in a pair of planar sawtooth gratings with mirror-imaged patterns. Significant multipolar effects were observed in the polarization-dependent SHG curves. We show that the chirality of the nanostructure not only give rise to nonzero chiral susceptibility tensor components within the electric-dipole approximation, but also lead to different levels of multipolar interactions for the two orthogonal circular polarizations that further enhance the nonlinear optical activity of the material. Our results thus indicate novel ways to optimize nonlinear plasmonic structures and achieve giant chiroptical response via multipolar interactions.
Collapse
|
35
|
Zeng Z, Mendis MN, Waldeck DH, Wei J. A semi-analytical decomposition analysis of surface plasmon generation and the optimal nanoledge plasmonic device. RSC Adv 2016; 6:17196-17203. [PMID: 26977289 PMCID: PMC4788070 DOI: 10.1039/c6ra01105e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Surface plasmon resonance (SPR) of nanostructured thin metal films (so-called nanoplasmonics) has attracted intense attention due to its versatility for optical sensing and chip-based device integration. Understanding the underlying physics and developing applications of nanoplasmonic devices with desirable optical properties, e.g. intensity of light scattering and high refractive index (RI) sensitivity at the perforated metal film, is crucial for practical uses in physics, biomedical detection, and environmental monitoring. This work presents a semi-analytical model that enables decomposition and quantitative analysis of surface plasmon generation at a new complex nanoledge aperture structure under plane-wave illumination, thus providing insight on how to optimize plasmonic devices for optimal plasmonic generation efficiencies and RI sensitivity. A factor analysis of parameters (geometric, dielectric-RI, and incident wavelength) relevant to surface plasmon generation is quantitatively investigated to predict the surface plasmon polariton (SPP) generation efficiency. In concert with the analytical treatment, a finite-difference time-domain (FDTD) simulation is used to model the optical transmission spectra and RI sensitivity as a function of the nanoledge device's geometric parameters, and it shows good agreement with the analytical model. Further validation of the analytical approach is provided by fabricating subwavelength nanoledge devices and testing their optical transmission and RI sensitivity.
Collapse
Affiliation(s)
- Zheng Zeng
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA
| | - Madu N. Mendis
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - David H. Waldeck
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jianjun Wei
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA
| |
Collapse
|
36
|
Formation of Enhanced Uniform Chiral Fields in Symmetric Dimer Nanostructures. Sci Rep 2015; 5:17534. [PMID: 26621558 PMCID: PMC4664915 DOI: 10.1038/srep17534] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 11/02/2015] [Indexed: 11/23/2022] Open
Abstract
Chiral fields with large optical chirality are very important in chiral molecules analysis, sensing and other measurements. Plasmonic nanostructures have been proposed to realize such super chiral fields for enhancing weak chiral signals. However, most of them cannot provide uniform chiral near-fields close to the structures, which makes these nanostructures not so efficient for applications. Plasmonic helical nanostructures and blocked squares have been proved to provide uniform chiral near-fields, but structure fabrication is a challenge. In this paper, we show that very simple plasmonic dimer structures can provide uniform chiral fields in the gaps with large enhancement of both near electric fields and chiral fields under linearly polarized light illumination with polarization off the dimer axis at dipole resonance. An analytical dipole model is utilized to explain this behavior theoretically. 30 times of volume averaged chiral field enhancement is gotten in the whole gap. Chiral fields with opposite handedness can be obtained simply by changing the polarization to the other side of the dimer axis. It is especially useful in Raman optical activity measurement and chiral sensing of small quantity of chiral molecule.
Collapse
|
37
|
Abstract
Chiral nanoplasmonics exhibits great potential for novel nanooptical devices due to the generation of a strong chiroptical response within nanoscale metallic structures. Recently, a number of different approaches have been utilized to create chiral nanoplasmonic structures. However, particularly for tailoring nanooptical chiral sensing devices, the understanding of the resulting chiroptical response when coupling chiral and achiral structures together is crucial and has not been completely understood to date. Here, we present a thorough and step-by-step experimental study to understand the intriguing chiral-achiral coupling scheme. We set up a hybrid plasmonic system, which bears resemblance to the 'host-guest' system in supramolecular chemistry to analyze and explain the complex chiral response both at the chiral and achiral plasmonic resonances. We also provide an elegant and simple analytical model, which can describe, predict, and comprehend the chiroptical spectra in detail. Our study will shed light on designing well-controlled chiral-achiral coupling platforms for reliable chiral sensing.
Collapse
Affiliation(s)
- Xiaoyang Duan
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, D-70569 Stuttgart, Germany.
| | | | | |
Collapse
|
38
|
Zhang W, Wang Y, Wen X, Zhang Z. Giant circular dichroism induced by silver nanocuboid heterodimers. APPLIED OPTICS 2015; 54:9359-9363. [PMID: 26560593 DOI: 10.1364/ao.54.009359] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Metallic nanocuboid heterodimers are proposed to generate a giant circular dichroism (CD) effect. Two cuboids in the heterodimers have different heights. The dipole and quadrupole charge oscillation modes in the cuboids occur under left- and right-handed circular polarizations. The height difference generates phase difference between charge oscillations in the two cuboids. The two charge oscillations and the phase difference between them are consistent with the Born-Kuhn model for the CD effect. The CD effect of the nanocuboid heterodimers can be tuned by changing the structural parameters of the nanocuboid heterodimers, especially the height difference between two cuboids. The results of this research are not only useful for designing plasmonic structures to generate the CD effect but also for understanding the physical mechanisms of the CD effect.
Collapse
|
39
|
Karimullah AS, Jack C, Tullius R, Rotello VM, Cooke G, Gadegaard N, Barron LD, Kadodwala M. Disposable Plasmonics: Plastic Templated Plasmonic Metamaterials with Tunable Chirality. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:5610-6. [PMID: 26306427 DOI: 10.1002/adma.201501816] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 07/02/2015] [Indexed: 05/27/2023]
Abstract
Development of low-cost disposable plasmonic substrates is vital for the applicability of plasmonic sensing. Such devices can be made using injection-molded templates to create plasmonic films. The elements of these plasmonic films are hybrid nanostructures composed of inverse and solid structures. Tuning the modal coupling between the two allows optimization of the optical properties for nanophotonic applications.
Collapse
Affiliation(s)
- Affar S Karimullah
- School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, G12 8QQ, UK
| | - Calum Jack
- School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, G12 8QQ, UK
| | - Ryan Tullius
- School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, G12 8QQ, UK
| | - Vincent M Rotello
- Department of Chemistry, University of Massachusetts Amherst, 710 Nt. Pleasant Street, MA, 01003, USA
| | - Graeme Cooke
- School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, G12 8QQ, UK
| | - Nikolaj Gadegaard
- School of Engineering, University of Glasgow, Rankine Building, Glasgow, G12 8QQ, UK
| | - Laurence D Barron
- School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, G12 8QQ, UK
| | - Malcolm Kadodwala
- School of Chemistry, University of Glasgow, Joseph Black Building, Glasgow, G12 8QQ, UK
| |
Collapse
|
40
|
Enhancement of Chiroptical Signals by Circular Differential Mie Scattering of Nanoparticles. Sci Rep 2015; 5:14463. [PMID: 26403593 PMCID: PMC4585887 DOI: 10.1038/srep14463] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/28/2015] [Indexed: 11/13/2022] Open
Abstract
We enhance the weak optical signals of small chiral molecules via circular differential Mie scattering (CDMS) of nanoparticles immersed in them. CDMS is the preferential Mie scattering of left- and right-handed circularly polarized light by nanoparticles whose sizes are about the same as the wavelength of light. Solving the Mie scattering theory for chiral media, we find that the CDMS signal of the particle is linearly proportional to the chirality parameter κ of the molecules. This linear amplitude enhancement by CDMS of the particle holds, even for large particles, which have a retardation effect. We also demonstrate that the CDMS of a nanoparticle is sensitive to changes of molecular concentration, and that the nanoparticle can be utilized as a chiroptical biosensor detecting the concentration of analyte. We expect that the enhancement of molecular chiroptical signals by CDMS will pave the way for novel chiroptical spectroscopy using nanostructures.
Collapse
|
41
|
Tullius R, Karimullah AS, Rodier M, Fitzpatrick B, Gadegaard N, Barron LD, Rotello VM, Cooke G, Lapthorn A, Kadodwala M. "Superchiral" Spectroscopy: Detection of Protein Higher Order Hierarchical Structure with Chiral Plasmonic Nanostructures. J Am Chem Soc 2015; 137:8380-3. [PMID: 26102606 DOI: 10.1021/jacs.5b04806] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Optical spectroscopic methods do not routinely provide information on higher order hierarchical structure (tertiary/quaternary) of biological macromolecules and assemblies. This necessitates the use of time-consuming and material intensive techniques, such as protein crystallography, NMR, and electron microscopy. Here we demonstrate a spectroscopic phenomenon, superchiral polarimetry, which can rapidly characterize ligand-induced changes in protein higher order (tertiary/quaternary) structure at the picogram level, which is undetectable using conventional CD spectroscopy. This is achieved by utilizing the enhanced sensitivity of superchiral evanescent fields to mesoscale chiral structure.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Vincent M Rotello
- §Department of Chemistry, University of Massachusetts Amherst, Massachusetts 01003, United States
| | | | | | | |
Collapse
|
42
|
Yoo S, Park QH. Chiral Light-Matter Interaction in Optical Resonators. PHYSICAL REVIEW LETTERS 2015; 114:203003. [PMID: 26047227 DOI: 10.1103/physrevlett.114.203003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Indexed: 05/20/2023]
Abstract
The Purcell effect explains the modification of the spontaneous decay rate of quantum emitters in a resonant cavity. For quantum emitters such as chiral molecules, however, the cavity modification of the spontaneous decay rate has been little known. Here we extend Purcell's work to the chiral light-matter interaction in optical resonators and find the differential spontaneous decay rate of chiral molecules coupled to left and right circularly polarized resonator modes. We determine the chiral Purcell factor, which characterizes the ability of optical resonators to enhance chiroptical signals, by the quality factor and the chiral mode volume of a resonator, representing, respectively, the temporal confinement of light and the spatial confinement of the helicity of light. We show that the chiral Purcell effect can be applied to chiroptical spectroscopy. Specifically, we propose a realistic scheme to achieve resonator enhanced chiroptical spectroscopy that uses the double fishnet structure as a nanoscale cuvette supporting the chiral Purcell effect.
Collapse
Affiliation(s)
- SeokJae Yoo
- Department of Physics, Korea University, Seoul, 136-713, Korea
| | - Q-Han Park
- Department of Physics, Korea University, Seoul, 136-713, Korea
| |
Collapse
|
43
|
Okamoto H, Narushima T, Nishiyama Y, Imura K. Local optical responses of plasmon resonances visualised by near-field optical imaging. Phys Chem Chem Phys 2015; 17:6192-206. [DOI: 10.1039/c4cp05951d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Near-field optical imaging visualises spatial features of plasmon resonances that cause unique optical characteristics of noble metal nanostructures.
Collapse
Affiliation(s)
- Hiromi Okamoto
- Institute for Molecular Science
- Okazaki
- Japan
- The Graduate University for Advanced Studies
- Okazaki
| | - Tetsuya Narushima
- Institute for Molecular Science
- Okazaki
- Japan
- The Graduate University for Advanced Studies
- Okazaki
| | | | - Kohei Imura
- Department of Chemistry and Biochemistry
- School of Science and Engineering
- Waseda University
- Shinjuku
- Japan
| |
Collapse
|
44
|
Oates TWH, Shaykhutdinov T, Wagner T, Furchner A, Hinrichs K. Gyrotropy in achiral materials: the coupled oscillator model. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:7197-7201. [PMID: 25207833 DOI: 10.1002/adma.201402012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 08/05/2014] [Indexed: 06/03/2023]
Abstract
A coupled oscillator model is developed to explain the observation of gyrotropy in achiral metamaterials. By the action of distinct excitation modes, which only combine under oblique incidence, the measurement of circular birefringence in a split-ring resonator (SRR) array is explained. The symmetry of the SRR resembles the water molecule, and parallels between the systems are drawn.
Collapse
Affiliation(s)
- Thomas W H Oates
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Albert Einstein Str. 9, 12489, Berlin, Germany
| | | | | | | | | |
Collapse
|
45
|
Angular momentum-induced circular dichroism in non-chiral nanostructures. Nat Commun 2014; 5:4922. [DOI: 10.1038/ncomms5922] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 08/06/2014] [Indexed: 11/08/2022] Open
|
46
|
Bliokh KY, Kivshar YS, Nori F. Magnetoelectric effects in local light-matter interactions. PHYSICAL REVIEW LETTERS 2014; 113:033601. [PMID: 25083644 DOI: 10.1103/physrevlett.113.033601] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Indexed: 06/03/2023]
Abstract
We study the generic dipole interaction of a monochromatic free-space electromagnetic field with a bi-isotropic nanoparticle or a molecule. Contributions associated with the breaking of dual, P, and T symmetries are responsible for electric-magnetic asymmetry, chirality, and the nonreciprocal magnetoelectric effect, respectively. We calculate absorption rates, radiation forces, and radiation torques for the nanoparticle and introduce novel field characteristics quantifying the transfer of energy, momentum, and angular momentum due to the three symmetry-breaking effects. In particular, we put forward a concept of "magnetoelectric energy density," quantifying the local PT symmetry of the field. Akin to the "superchiral" light suggested recently for local probing of molecular chirality, here we suggest employing complex fields for a sensitive probing of the nonreciprocal magnetoelectric effect in nanoparticles or molecules.
Collapse
Affiliation(s)
- Konstantin Y Bliokh
- iTHES Research Group, RIKEN, Wako-shi, Saitama 351-0198, Japan and CEMS, RIKEN, Wako-shi, Saitama 351-0198, Japan
| | - Yuri S Kivshar
- Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200, Australia
| | - Franco Nori
- CEMS, RIKEN, Wako-shi, Saitama 351-0198, Japan and Physics Department, University of Michigan, Ann Arbor, Michigan 48109-1040, USA
| |
Collapse
|
47
|
Armelles G, Caballero B, Prieto P, García F, Cebollada A, González MU, García-Martin A. Magnetic field modulation of chirooptical effects in magnetoplasmonic structures. NANOSCALE 2014; 6:3737-41. [PMID: 24569696 DOI: 10.1039/c3nr05889a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
In this work we analyse the magnetic field effects on the chirooptical properties of magnetoplasmonic chiral structures. The structures consist of two-dimensional arrays of Au gammadions in which thin layers of Co have been inserted. Due to the magnetic properties of the Au/Co interface the structures have perpendicular magnetic anisotropy which favours magnetic saturation along the surface normal, allowing magnetic field modulation of the chirooptical response with moderate magnetic fields. These structures have two main resonances. The resonance at 850 nm has a larger chirooptical response than the resonance at 650 nm, which, on the other hand, exhibits a larger magnetic field modulation of its chirooptical response. This dissimilar behaviour is due to the different physical origin of the chirooptical and magneto-optical responses. Whereas the chirooptical effects are due to the geometry of the structures, the magneto-optical response is related to the intensity of the electromagnetic field in the magnetic (Co) layers. We also show that the optical chirality can be modulated by the applied magnetic field, which suggests that magnetoplasmonic chiral structures could be used to develop new strategies for chirooptical sensing.
Collapse
Affiliation(s)
- Gaspar Armelles
- IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, E-28760, Tres Cantos, Madrid, Spain.
| | | | | | | | | | | | | |
Collapse
|
48
|
Lin D, Huang JS. Slant-gap plasmonic nanoantennas for optical chirality engineering and circular dichroism enhancement. OPTICS EXPRESS 2014; 22:7434-45. [PMID: 24718118 DOI: 10.1364/oe.22.007434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We present a new design of plasmonic nanoantenna with slant gap for optical chirality engineering. At resonance, the slant gap provides highly enhanced electric field parallel to external magnetic field with a phase delay of π/2, resulting in enhanced optical chirality. We show by numerical simulations that upon linearly polarized excitation our nanoantenna can generate near field with enhanced optical chirality which can be tuned by the slant angle and resonance condition. Our design allows chiral analysis with linearly polarized light and may find applications in circular dichroism analysis of chiral matter at surface.
Collapse
|
49
|
Hentschel M, Schäferling M, Metzger B, Giessen H. Plasmonic diastereomers: adding up chiral centers. NANO LETTERS 2013; 13:600-6. [PMID: 23272699 DOI: 10.1021/nl3041355] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We construct chiral plasmonic molecules by assembling two individual chiral centers. Interestingly, depending on the exact arrangement of the centers, all combinations result in a chiral compound with a strong chiral optical response. Furthermore, we demonstrate that the overall circular dichrosim (CD) is determined by the response of the individual chiral centers. We find that the CD spectra of the composite molecules are then simply given as the sum of the CD spectra of the constituting building blocks. Interestingly, as soon as strong near-field coupling takes place between chiral centers, we find strong deviation from the simple additive chiral behavior. Most importantly, we demonstrate that the optical response of complex chiral plasmonic systems can be decomposed and understood in terms of fundamental building blocks, offering simple and straightforward design rules for future applications such as chiral optical elements and enantiomer sensors.
Collapse
Affiliation(s)
- Mario Hentschel
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
| | | | | | | |
Collapse
|
50
|
Yin X, Schäferling M, Metzger B, Giessen H. Interpreting chiral nanophotonic spectra: the plasmonic Born-Kuhn model. NANO LETTERS 2013; 13:6238-43. [PMID: 24219560 DOI: 10.1021/nl403705k] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
One of the most intuitive ways to classically understand the generation of natural optical activity in chiral media is provided by the coupled oscillator model of Born and Kuhn consisting of two identical, vertically displaced, coupled oscillators. We experimentally realize and discuss its exact plasmonic analog in a system of corner-stacked gold nanorods. In particular, we analyze the arising circular dichroism and optical rotatory spectra in terms of hybridized electromagnetic modes and retardation. Specifically, we demonstrate how tuning the vertical distance between the nanorods can lead to a selective excitation of the occurring bonding and antibonding chiral plasmonic modes.
Collapse
Affiliation(s)
- Xinghui Yin
- 4th Physics Institute and Research Center SCoPE, University of Stuttgart , Pfaffenwaldring 57, D-70569 Stuttgart, Germany
| | | | | | | |
Collapse
|