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Phase imaging of transition from classical to quantum plasmonic couplings between a metal nanoparticle and a metal surface.

ABSTRACT: When a metal nanoparticle is brought near to a metal surface within electron tunneling distance (?1 nm), classical electromagnetic coupling between the nanoparticle and the metal is expected to transition to quantum coupling. We show that this transition can be observed as a drastic phase change in the surface plasmon resonance (SPR) images of the gold nanoparticles. We study the transition by controlling the distance between the nanoparticles and electrode surface, modeling the impact of the transition on the SPR image in terms of a phase shift and demonstrating detection of microRNA based on the transition from classical to quantum coupling. The work shows that the quantum coupling can be directly visualized in SPR, and the extremely sensitive dependence of the transition on distance leads to a biosensing principle with SPR.

SUBMITTER: Wang H

PROVIDER: S-EPMC7395563 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

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Phase imaging of transition from classical to quantum plasmonic couplings between a metal nanoparticle and a metal surface.

Wang Hui H Yu Hui H Wang Yan Y Shan Xiaonan X Chen Hong-Yuan HY Tao Nongjian N

Proceedings of the National Academy of Sciences of the United States of America 20200714 30

When a metal nanoparticle is brought near to a metal surface within electron tunneling distance (∼1 nm), classical electromagnetic coupling between the nanoparticle and the metal is expected to transition to quantum coupling. We show that this transition can be observed as a drastic phase change in the surface plasmon resonance (SPR) images of the gold nanoparticles. We study the transition by controlling the distance between the nanoparticles and electrode surface, modeling the impact of the tr ...[more]

PMID: 32665434

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