Title: Plasmonic circular dichroism of vesicle-like nanostructures by the template-less self-assembly of achiral Janus nanoparticles

Abstract

Chiral nanostructures have been attracting extensive interest in recent years primarily because of the unique materials properties that can be exploited for diverse applications. In this study, gold Janus nanoparticles, with hexanethiolates and 3-mercapto-1,2-propanediol segregated on the two hemispheres of the metal cores (dia. 2.7 ± 0.4 nm), self-assembled into vesicle-like, hollow nanostructures in both water or organic media, and exhibited apparent plasmonic circular dichroism (PCD) absorption in the visible range. This was in contrast to individual Janus nanoparticles, bulk-exchange nanoparticles where the two ligands were homogeneously mixed on the nanoparticle surface, or nanoparticles capped with only one kind of the ligands. The PCD signals were found to become intensified with increasing coverage of the 3-mercapto-1,2-propanediol ligands on the nanoparticle surface. This was accounted for by the dipolar property of the structurally asymmetrical Janus nanoparticles, and theoretical simulations based on first principles calculations showed that when the nanoparticle dipoles self-assembled onto the surface of a hollow sphere, a vortex was formed which gave rise to the unique chiral characteristics. The resulting chiral nanoparticle vesicles could be exploited for the separation of optical enantiomers, as manifested in the selective identification and separation of D-alanine from the L-isomer

Authors:

Lu, Jia En ^[1]; Yang, Chou-Hsun  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-8088-7072"
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Wang, Haobin  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-3532-7770"
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Yam, ChiYung  ^[3];

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Yu, Zhi-Gang  ^[4];

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• Search DOE PAGES for ORCID "0000-0002-1376-9025"
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Chen, Shaowei  ^[1]

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• Search DOE PAGES for ORCID "0000-0002-3668-8551"
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+ Show Author Affiliations

1. Univ. of California, Santa Cruz, CA (United States)
2. Univ. of Colorado, Denver, CO (United States)
3. Beijing Computational Science Research Center, Beijing (China)
4. Washington State Univ., Pullman, WA (United States)

Publication Date:

2018-07-12

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of California, Oakland, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC)

OSTI Identifier:

1543812

Alternate Identifier(s):

OSTI ID: 1461017

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Nanoscale

Additional Journal Information:

Journal Volume: 10; Journal Issue: 30; Journal ID: ISSN 2040-3364

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Chemistry; Science & Technology - Other Topics; Materials Science; Physics