Corporate Banner
Satellite Banner
Metabolomics & Lipidomics
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Tiny Probes Shine Brightly to Reveal the Location of Targeted Tissues

Published: Friday, November 23, 2012
Last Updated: Friday, November 23, 2012
Bookmark and Share
Called BRIGHTs, the tiny probes described in the online issue of Advanced Materials, bind to biomarkers of disease and, when swept by an infrared laser, light up to reveal their location.

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.


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,400+ scientific posters on ePosters
  • More than 4,900+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Clearance of Key Alzheimer’s Protein Dramatically Slows with Age
Researchers at Washington University School of Medicine in St. Louis have identified some of the key changes in the aging brain that lead to an increased risk of Alzheimer's.
Tuesday, August 11, 2015
$4.7 Million Study Looks at Why Diabetes Makes Heart Disease Worse
Washington University researchers receives a $4.7 million grant from NHLBI.
Wednesday, July 18, 2012
Scientific News
Demonstrating LNP Delivery of CRISPR Components
Intellia has presented data demonstrating in vivo gene editing ising liquid nanoparticles (LNPs) to deliver CRISPR/Cas9.
Russian TB Thrives Within Macrophages
MIPT researchers have identified features of mycobacterium tuberculosis strains that may explain their success.
Ginger Nanoparticles Heal Bowel Disease
Lab team spins ginger into nanoparticles to heal inflammatory bowel disease.
Examining New Hypotheses for Undiagnosed Patients
UnDx Consortium gathers in San Diego to create new paths to identifying currently undiagnosed illnesses.
Expanding the Stable of Workhorse Yeasts
New genome sequences target the next generation of yeasts with improved biotechnology uses.
How Cloud Connectivity Can Combat the Reproducibility Crisis
This infographic explains the reproducibility crisis, and how cloud connectivity can help overcome this problem.
Accessing Metabolic Information with Mass Spec
Scientists at the Helmholtz Zentrum München have developed a new mass spectrometry imaging method which, for the first time, makes it possible to analyze hundreds of metabolites in fixed tissue samples.
Improving Tumour Therapy with Nanoparticles
UHN nanoparticle called PEARLs is a promising utilisation of photo-thermal therapy for cancer treatment.
Exosome Research and Quality Control Using ZetaView
Particle Matrix's ZetaView particle characterisation system used by Cell Guidance Systems for exosome research.
Natural Metabolite Can Suppress Inflammation
An international group of scientists from US, Canada, Germany and Russia has revealed a substance produced in humans that can suppress the pro-inflammatory activity of macrophages – specific cells of immune system.
Skyscraper Banner

SELECTBIO Market Reports
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,400+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,900+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!