Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Optical imaging enters sub-nanometer era

Schematic of the experimental set-up for single-molecule photoluminescence imaging with sub-nanometer resolution

CREDIT
YANG Ben, HUANG Wen et al.
Schematic of the experimental set-up for single-molecule photoluminescence imaging with sub-nanometer resolution CREDIT YANG Ben, HUANG Wen et al.

Abstract:
Prof. DONG Zhenchao and Prof. HOU Jianguo from University of Science and Technology of China (USTC) of Chinese Academy of Sciences (CAS) improved the spatial resolution from 8 nm to ~8 of photoluminescence imaging. It realized sub-molecular resolution with single molecule photofluorescence imaging for the first time.

Optical imaging enters sub-nanometer era

Beijing, China | Posted on August 28th, 2020

This study was published in Nature Photonics on August 10.

To reach atomic resolution with light has always been one of the ultimate goals in nano-optics. The advent of scanning near-field optical microscopy (SNOM) kindled hopes for the goal.

Prof. DONG and his colleagues successfully demonstrated sub-nanometer scale spatial resolution in the single-molecule Raman spectroscopy imaging with local enhancement effect of a nanocavity plasmon field in a study in 2013.

However, unlike the Raman scattering process, fluorescence will be quenched in the very immediate vicinity of metals which stops the resolution development of SNOM at around 10 nm.

The radiation properties (fluorescence) of molecules in the metal nanocavity are directly affected by the photon density of the nanocavity , and the photon density of the nanocavity is closely related to the structure of the probe tip. Therefore, it is the key to modify the structure of the probe and the electronic state of the molecules in the nanocavity to avoid the fluorescence quenching and achieve high-resolution photofluorescence imaging.

DONG's team further fine-tuned the plasmon nanocavity, especially in the fabrication and control of the atomic-level structure of the probe tip. They constructed an Ag tip apex with an atomistic protrusion and matched the nanocavity plasmon resonance with the effective energy of the incident laser and molecular luminescence.

Then, the researchers used an ultra-thin dielectric layer (three-atom-thick NaCl) to isolate the charge transfer between the nanocavity molecules and the metal substrate, achieving sub-nanometer resolution of the single-molecule photoluminescence imaging.

They found that with the probe approaching the molecule, even if their distance is less than 1 nm, the intensity of photoluminescence continues increasing monotonously. And the fluorescence quenching disappears completely.

Theoretical simulations showed that when the atomistic protrusion tip and the metal substrate form a plasmon nanocavity, the resonance response of the nanocavity plasmon and the lightning rod effect of the atomistic protrusion structure would have a synergistic effect. The synergistic effect generates a strong and highly localized electromagnetic field compressing the cavity mode volume to below 1 nm3, which greatly increases the localized photon density of states and the molecular radiation decay rate. These effects not only inhibit the fluorescence quenching, but also realize sub-nanometer-resolution photoluminescence imaging.

To achieve sub-nanometer spatial resolution, the size of the tip and the distance between the tip and the sample must be on the sub-nanometer scale.

The researchers further realized sub-molecular-resolved photoluminescence hyperspectral imaging with spectral information, and demonstrated the effects of local plasmon-exciton interaction on fluorescence intensity, peak position and peak width on the sub-nanometer scale.

This research achieved the long-awaited goal of using light to analyze the internal structure of molecules in SNOM, and provided a new technical method for detecting and modulating the localized environment of molecules and light-matter interactions on the sub-nanometer scale.

The reviewers of Nature Photonics say that this paper will be an important article in its field, which has guiding significance for carrying out ultra-sensitive spectroscopic microscopy research with atomic-scale light.

###

####

For more information, please click here

Contacts:
Jane FAN Qiong

86-551-636-07280

Copyright © University of Science and Technology of China (USTC)

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

RELATED JOURNAL ARTICLE:

Related News Press

Imaging

Previously unknown pathway to batteries with high energy, low cost and long life: Newly discovered reaction mechanism overcomes rapid performance decline in lithium-sulfur batteries September 8th, 2023

News and information

Chung-Ang University researchers develop novel DNA biosensor for early diagnosis of cervical cancer: The electrochemical sensor, made of a graphitic nano-onion/molybdenum disulfide nanosheet composite, detects human papillomavirus (HPV)-16 and HPV-18, with high specificity September 8th, 2023

New compound unleashes the immune system on metastases September 8th, 2023

Machine learning contributes to better quantum error correction September 8th, 2023

Tests find no free-standing nanotubes released from tire tread wear September 8th, 2023

Possible Futures

Chung-Ang University researchers develop novel DNA biosensor for early diagnosis of cervical cancer: The electrochemical sensor, made of a graphitic nano-onion/molybdenum disulfide nanosheet composite, detects human papillomavirus (HPV)-16 and HPV-18, with high specificity September 8th, 2023

New compound unleashes the immune system on metastases September 8th, 2023

Machine learning contributes to better quantum error correction September 8th, 2023

Tests find no free-standing nanotubes released from tire tread wear September 8th, 2023

Discoveries

Electronic detection of DNA nanoballs enables simple pathogen detection Peer-Reviewed Publication September 8th, 2023

Training quantum computers: physicists win prestigious IBM Award September 8th, 2023

Unlocking quantum potential: Harnessing high-dimensional quantum states with QDs and OAM: Generation of nearly deterministic OAM-based entangled states offers a bridge between photonic technologies for quantum advancements September 8th, 2023

Tests find no free-standing nanotubes released from tire tread wear September 8th, 2023

Announcements

Electronic detection of DNA nanoballs enables simple pathogen detection Peer-Reviewed Publication September 8th, 2023

Training quantum computers: physicists win prestigious IBM Award September 8th, 2023

Machine learning contributes to better quantum error correction September 8th, 2023

Tests find no free-standing nanotubes released from tire tread wear September 8th, 2023

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters

Electronic detection of DNA nanoballs enables simple pathogen detection Peer-Reviewed Publication September 8th, 2023

Unlocking quantum potential: Harnessing high-dimensional quantum states with QDs and OAM: Generation of nearly deterministic OAM-based entangled states offers a bridge between photonic technologies for quantum advancements September 8th, 2023

Chung-Ang University researchers develop novel DNA biosensor for early diagnosis of cervical cancer: The electrochemical sensor, made of a graphitic nano-onion/molybdenum disulfide nanosheet composite, detects human papillomavirus (HPV)-16 and HPV-18, with high specificity September 8th, 2023

New compound unleashes the immune system on metastases September 8th, 2023

Tools

New single-photon Raman lidar can monitor for underwater oil leaks: System could be used aboard underwater vehicles for many applications June 30th, 2023

Research breakthrough could be significant for quantum computing future: Irish-based scientists confirm crucial characteristic of new superconductor material June 30th, 2023

Understanding the mechanism of non-uniform formation of diamond film on tools: Paving the way to a dry process with less environmental impact March 24th, 2023

Researchers develop innovative tool for measuring electron dynamics in semiconductors: Insights may lead to more energy-efficient chips and electronic devices March 3rd, 2023

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project