Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > So BRIGHT, you need to wear shades: Tiny probes shine brightly to reveal the location of targeted tissues

NAVEEN GANDRA
Nanostructures called BRIGHTs seek out biomarkers on cells and then beam brightly to reveal their locations. In the tiny gap between the gold skin and the gold core of the cleaved BRIGHT (visible to the upper left), there is an electromagnetic hot spot that lights up the reporter molecules trapped there.
NAVEEN GANDRA

Nanostructures called BRIGHTs seek out biomarkers on cells and then beam brightly to reveal their locations. In the tiny gap between the gold skin and the gold core of the cleaved BRIGHT (visible to the upper left), there is an electromagnetic hot spot that lights up the reporter molecules trapped there.

Abstract:
Called BRIGHTs, the tiny probes described in the online issue of Advanced Materials on Nov. 15, bind to biomarkers of disease and, when swept by an infrared laser, light up to reveal their location.

So BRIGHT, you need to wear shades: Tiny probes shine brightly to reveal the location of targeted tissues

St. Louis, MO | Posted on November 20th, 2012

Tiny as they are, the probes are exquisitely engineered objects: gold nanoparticles covered with molecules called Raman reporters, in turn covered by a thin shell of gold that spontaneously forms a dodecahedron.

The Raman reporters are molecules whose jiggling atoms respond to a probe laser by scattering light at characteristic wavelengths.

The shell and core create an electromagnetic hotspot in the gap between them that boosts the reporters' emission by a factor of nearly a trillion.

BRIGHTs shine about 1.7 x 1011 more brightly than isolated Raman reporters and about 20 times more intensely than the next-closest competitor probe, says Srikanth Singamaneni, PhD, assistant professor of mechanical engineering and materials science in the School of Engineering & Applied Science at Washington University in St. Louis.

Goosing the signal from Raman reporters
Singamaneni and his postdoctoral research associate Naveen Gandra, PhD, tried several different probe designs before settling on BRIGHTS.

Singamaneni's lab has worked for years with Raman spectroscopy, a spectroscopic technique that is used to study the vibrational modes (bending and stretching) of molecules. Laser light interacts with these modes and the molecule then emits light at higher or lower wavelengths that are characteristic of the molecule,

Spontaneous Raman scattering, as this phenomenon is called, is by nature very weak, but 30 years ago scientists accidently stumbled on the fact that it is much stronger if the molecules are adsorbed on roughened metallic surfaces. Then they discovered that molecules attached to metallic nanoparticles shine even brighter than those attached to rough surfaces.

The intensity boost from surface-enhanced Raman scattering, or SERS, is potentially huge. "It's well-known that if you sandwich Raman reporters between two plasmonic materials, such as gold or silver, you are going to see dramatic Raman enhancement," Singamaneni says.

Originally his team tried to create intense electromagnetic hot spots by sticking smaller particles onto a larger central particle, creating core-satellite assemblies that look like daisies.

"But we realized these assemblies are not ideal for bioimaging," he says, "because the particles were held together by weak electrostatic interactions and the assemblies were going to come apart in the body."

Next they tried using something called Click chemistry to make stronger covalent bonds between the satellites and the core.

"We had some success with those assemblies," Singamaneni says, "but in the meantime we had started to wonder if we couldn't make an electromagnetic hot spot within a single nanoparticle rather than among particles.

"It occurred to us that if we put Raman reporters between the core and shell of a single particle could we create an internal hotspot."

That idea worked like a charm.

A rainbow of probes carefully dispensing drugs?
The next step, says Singamaneni, is to test BRIGHTS in vivo in the lab of Sam Achilefu, PhD, professor of radiology in the School of Medicine.

But he's already thinking of ways to get even more out of the design.

Since different Raman reporter molecules respond at different wavelengths, Singamaneni says, it should be possible to design BRIGHTS targeted to different biomolecules that also have different Raman reporters and then monitor them all simultaneously with the same light probe.

And he and Gandra would like to combine BRIGHTS with a drug container of some kind, so that the containers could be tracked in the body and the drug and released only when it reached the target tissue, thus avoiding many of the side effects patients dread.

Good things, as they say, come in small packages.

####

For more information, please click here

Contacts:
Diana Lutz

314-935-5272

Copyright © Washington University in St. Louis

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 News Press

News and information

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Imaging

New material to make next generation of electronics faster and more efficient With the increase of new technology and artificial intelligence, the demand for efficient and powerful semiconductors continues to grow November 8th, 2024

Turning up the signal November 8th, 2024

New discovery aims to improve the design of microelectronic devices September 13th, 2024

Quantum researchers cause controlled ‘wobble’ in the nucleus of a single atom September 13th, 2024

Nanomedicine

Ben-Gurion University of the Negev researchers several steps closer to harnessing patient's own T-cells to fight off cancer June 6th, 2025

Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Self-propelled protein-based nanomotors for enhanced cancer therapy by inducing ferroptosis June 6th, 2025

Discoveries

Researchers unveil a groundbreaking clay-based solution to capture carbon dioxide and combat climate change June 6th, 2025

Cambridge chemists discover simple way to build bigger molecules – one carbon at a time June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Announcements

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Electrifying results shed light on graphene foam as a potential material for lab grown cartilage June 6th, 2025

Quantum computers simulate fundamental physics: shedding light on the building blocks of nature June 6th, 2025

A 1960s idea inspires NBI researchers to study hitherto inaccessible quantum states June 6th, 2025

Tools

Portable Raman analyzer detects hydrogen leaks from a distance: Device senses tiny concentration changes of hydrogen in ambient air, offering a dependable way to detect and locate leaks in pipelines and industrial systems April 25th, 2025

Rice researchers harness gravity to create low-cost device for rapid cell analysis February 28th, 2025

New 2D multifractal tools delve into Pollock's expressionism January 17th, 2025

New material to make next generation of electronics faster and more efficient With the increase of new technology and artificial intelligence, the demand for efficient and powerful semiconductors continues to grow November 8th, 2024

Photonics/Optics/Lasers

INRS and ELI deepen strategic partnership to train the next generation in laser science:PhD students will benefit from international mobility and privileged access to cutting-edge infrastructure June 6th, 2025

Institute for Nanoscience hosts annual proposal planning meeting May 16th, 2025

Following the folds – with quantum technology: The connection between a crumpled sheet of paper and quantum technology: A research team at the EPFL in Lausanne (Switzerland) and the University of Konstanz (Germany) uses topology in microwave photonics to make improved systems of May 16th, 2025

Programmable electron-induced color router array May 14th, 2025

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