Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Nanoshell-emitters hybrid nanoobject was proposed as promising 2-photon fluorescence probe

This is a schematic presentation of plasmonic-enhanced two-photon fluorescence of a single emitter inside or outside of an individual gold nanoshell.

Credit: ©Science China Press
This is a schematic presentation of plasmonic-enhanced two-photon fluorescence of a single emitter inside or outside of an individual gold nanoshell.

Credit: ©Science China Press

Abstract:
Two-photon excitation fluorescence is growing in popularity in the bioimaging field but is limited by fluorophores' extremely low two-photon absorption cross-section. The researcher Dr. Guowei Lu and co-workers from State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, are endeavoring to develop efficient fluorescent probes with improved two-photon fluorescence (TPF) performance. They theoretically present a promising bright probe using gold nanoshell to improve the TPF performances of fluorescent emitters. Their work, entitled "Plasmonic-Enhanced Two-Photon Fluorescence with Single Gold Nanoshell", was published in SCIENCE CHINA Physics, Mechanics & Astronomy.2014, Vol 57(6).

Nanoshell-emitters hybrid nanoobject was proposed as promising 2-photon fluorescence probe

Shenyang, PR China | Posted on May 22nd, 2014

The strategy of using metallic nanoparticles to achieve the TPF enhancement is an appealing scheme so-called metal-enhanced fluorescence. It is based on the coupling of the fluorophores and the plasmonic nanoparticles, resulting in enhanced fluorescence intensity, shortened fluorescence lifetime, and extended photostability. Specifically, the fluorescence enhancement can be optimally controlled through simultaneous efficient coupling between the excitation and emission processes of emitters and the dipolar and quadrupolar modes of the nanoparticles, respectively.

Among various types of metal nanoparticles, metallic nanoshells are especially suitable as the carriers of fluorescent emitters to construct hybrid TPF probes, because their plasmon resonance bands easily span the near-infrared region where biological tissues display minimal autofluorescence and absorption. The nanoshells act as optical antenna enabling the local field enhancement, the increase in radiative decay rate of the fluorophore that alters the quantum efficiency, and modulation of the far-field radiative coupling of fluorescence emission through nanoparticle scattering. Also, the core shell structure offers a perfect platform for designing and fabricating multifunctional nanoparticles.

The Peking University researchers employed the finite-difference time-domain method to systematically evaluate the two-photo fluorescence behavior of single emitter single nanoshell configuration. Simultaneous excitation and emission enhancements could be achieved by the suitable dimensions of the nanoshell. They found that the emitter located inside or outside the nanoshell at various positions led to significantly different enhancement effect. (as shown in the Figure).

The fluorescent emitter placed outside the nanoshell can achieve large fluorescence intensity given that both the position and orientation of the emission dipole are optimally controlled, but the TPF enhancement decays rapidly with the increase of distance between the emitter and the shell surface. In contrast, for the case of the emitter placed inside the nanoshell, it can experience substantial two-photon fluorescence enhancement without strict requirements upon the position and dipole orientations, the radiative light can be coupled efficiently with the far field. Besides, the metal shell protects the encapsulated fluorophores from the external environment. The stability of fluorophores can be improved by the strong coupling between the fluorophores and the nanoshell resulting in a shorter fluorescence lifetime. These considerations imply that fluorophores encapsulated in metallic nanoshells is a more desirable nanocomposite configuration for the TPF probe in bioimaging applications.

This work provides a comprehensive understanding about the plasmonic-enhanced two-photon fluorescence behaviors, and the nanocomposite configuration has great potential for optical detecting, imaging and sensing in biological applications.

###

The paper's co-authors are Peking University graduate students Zhang Tianyue, Shen Hongming and collaborative scientists Perriat, P.; Martini, M.; Tillement, O. from CNRS, France. This research project was supported by a grant from the National Natural Science Foundation of China and the National Key Basic Research Program of China.

####

For more information, please click here

Contacts:
LU Guowei

Copyright © Science China Press

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

See the article: ZHANG TianYue, LU GuoWei, SHEN HongMing, Perriat P, Martini M, Tillement O, GONG QiHuang. Plasmonic-enhanced two-photon fluorescence with single gold nanoshell. SCIENCE CHINA Physics, Mechanics & Astronomy, 2014, 57 (6): 1038-1045:

Related News Press

News and information

Strength of hair inspires new materials for body armor January 18th, 2017

Self-assembling particles brighten future of LED lighting January 18th, 2017

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Imaging

Distinguishing truth under the surface: electrostatic or mechanic December 31st, 2016

Nanoscale 'conversations' create complex, multi-layered structures: New technique leverages controlled interactions across surfaces to create self-assembled materials with unprecedented complexity December 22nd, 2016

Safe and inexpensive hydrogen production as a future energy source: Osaka University researchers develop efficient 'green' hydrogen production system that operates at room temperature in air December 21st, 2016

First use of graphene to detect cancer cells: System able to detect activity level of single interfaced cell December 20th, 2016

Sensors

Nanoscale Modifications can be used to Engineer Electrical Contacts for Nanodevices January 13th, 2017

Researchers create practical and versatile microscopic optomechanical device: Trapping light and mechanical waves within a tiny bullseye, design could enable more sensitive motion detection January 11th, 2017

STMicroelectronics Peps Up Booming Social-Fitness Scene with Smart Motion Sensors for Better Accuracy, Longer Battery Life, and Faster Time to Market January 2nd, 2017

Advance in intense pulsed light sintering opens door to improved electronics manufacturing December 23rd, 2016

Discoveries

Strength of hair inspires new materials for body armor January 18th, 2017

Self-assembling particles brighten future of LED lighting January 18th, 2017

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Announcements

Strength of hair inspires new materials for body armor January 18th, 2017

Self-assembling particles brighten future of LED lighting January 18th, 2017

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

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

Strength of hair inspires new materials for body armor January 18th, 2017

Self-assembling particles brighten future of LED lighting January 18th, 2017

Dressing a metal in various colors: DGIST research developed a technology to coat metal with several nanometers of semiconducting materials January 17th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Nanobiotechnology

Nanoscale Modifications can be used to Engineer Electrical Contacts for Nanodevices January 13th, 2017

New active filaments mimic biology to transport nano-cargo: A new design for a fully biocompatible motility engine transports colloidal particles faster than diffusion with active filaments January 11th, 2017

Keystone Nano Announces FDA Approval Of Investigational New Drug Application For Ceramide NanoLiposome For The Improved Treatment Of Cancer January 10th, 2017

Captured on video: DNA nanotubes build a bridge between 2 molecular posts: Research may lead to new lines of direct communication with cells January 9th, 2017

Photonics/Optics/Lasers

Recreating conditions inside stars with compact lasers: Scientists offer a new path to creating the extreme conditions found in stars, using ultra-short laser pulses irradiating nanowires January 12th, 2017

New laser based on unusual physics phenomenon could improve telecommunications, computing January 12th, 2017

Researcher's discovery of new crystal structure holds promise for optoelectronic devices January 6th, 2017

The researchers created a tiny laser using nanoparticles January 5th, 2017

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




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project