Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Silver nanoparticles take spectroscopy to new dimension: A new way of organizing nanostructures has boosted Raman signals by a hundred thousand times to better identify and characterize different molecules

Detection of a low concentration analyte molecule using silicon nanowires decorated with silver nanoparticles and surface enhanced Raman scattering measurements.
CREDIT
V.S. Vendamani
Detection of a low concentration analyte molecule using silicon nanowires decorated with silver nanoparticles and surface enhanced Raman scattering measurements. CREDIT V.S. Vendamani

Abstract:
As medicine and pharmacology investigate nanoscale processes, it has become increasingly important to identify and characterize different molecules. Raman spectroscopy, a technique that leverages the scattering of laser light to identify molecules, has a limited capacity to detect molecules in diluted samples because of low signal yield.

Silver nanoparticles take spectroscopy to new dimension: A new way of organizing nanostructures has boosted Raman signals by a hundred thousand times to better identify and characterize different molecules

Washington, DC | Posted on January 2nd, 2018

A team of researchers from the University of Hyderabad in India has improved molecular detection at low concentration levels by arranging nanoparticles on nanowires to enhance Raman spectroscopy. Surface-enhanced Raman spectroscopy (SERS) uses electromagnetic fields to improve Raman scattering and boost sensitivity in standard dyes such as R6G by more than one billionfold.

The team decorated vertically aligned silicon nanowires with varying densities of silver nanoparticles, utilizing and enhancing the structure's 3-D shape. Their results, published in the Journal of Applied Physics, from AIP Publishing, show that their device was able to enhance the Raman signals for cytosine protein and ammonium perchlorate by a factor of 100,000.

"The beauty is that we can improve the density of these nanowires using simple chemistry," said Soma Venugopal Rao, one of the paper's authors. "If you have a large density of nanowires, you can put more silver nanoparticles into the substrate and can increase the sensitivity of the substrate."

Applying the necessary nanostructures to SERS devices remains a challenge for the field. Building these structures in three dimensions with silicon nanowires has garnered attention for their higher surface area and superior performance, but silicon nanowires are still expensive to produce.

Instead, the team was able to find a cheaper way to make silicon nanowires and used a technique called electroless etching to make a wide range of nanowires. They "decorated" these wires with silver nanoparticles with variable and controlled densities, which increased the nanowires' surface area.

"Optimizing these vertically aligned structures took a lot of time in the beginning," said Nageswara Rao, another of the paper's authors. "We increased the surface area and to do this we needed to change the aspect ratio."

After optimizing their system to detect Rhodamine dye on a nanomolar level, these new substrates the team built enhanced Raman sensitivity by a factor of 10,000 to 100,000. The substrates detected concentrations of cytosine, a nucleotide found in DNA, and ammonium perchlorate, a molecule with potential for detecting explosives, in as dilute concentrations as 50 and 10 micromolar, respectively.

The results have given the team reason to believe that it might soon be possible to detect compounds in concentrations on the scale of nanomolar or even picomolar, Nageswara Rao said. The team's work has opened several avenues for future research, from experimenting with different nanoparticles such as gold, increasing the sharpness of the nanowires or testing these devices across several types of molecules.

####

About American Institute of Physics
Journal of Applied Physics is an influential international journal publishing significant new experimental and theoretical results of applied physics research. See http://jap.aip.org .

For more information, please click here

Contacts:
Julia Majors

301-209-3090

Copyright © American Institute of Physics

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

The article, "Three-dimensional hybrid silicon nanostructures for surface enhanced Raman spectroscopy based molecular detection," is authored V.S. Vendamani, S.V.S. Nageswara Rao, S. Venugopal Rao, D. Kanjilal and A.P. Pathak. The article will appear in The Journal of Applied Physics Jan. 2, 2018 (DOI: 10.1063/1.5000994). After that date, it can be accessed at:

Related News Press

Imaging

Big award enables study of small surfaces: Rice U.'s Matt Jones wins Packard Fellowship to view nanoscale chemical reactions October 15th, 2018

News and information

Big award enables study of small surfaces: Rice U.'s Matt Jones wins Packard Fellowship to view nanoscale chemical reactions October 15th, 2018

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1 Study of ARO-ANG3 October 15th, 2018

Graphene shows unique potential to exceed bandwidth demands of future telecommunications October 12th, 2018

High-performance self-assembled catalyst for SOFC October 12th, 2018

Discoveries

Researchers quickly harvest 2-D materials, bringing them closer to commercialization: Efficient method for making single-atom-thick, wafer-scale materials opens up opportunities in flexible electronics October 12th, 2018

Graphene shows unique potential to exceed bandwidth demands of future telecommunications October 12th, 2018

High-performance self-assembled catalyst for SOFC October 12th, 2018

Tracking a Killer: UCSB, UCSD and SBP researchers trace the complex and variable pathways to the deadly condition known as sepsis October 12th, 2018

Announcements

Big award enables study of small surfaces: Rice U.'s Matt Jones wins Packard Fellowship to view nanoscale chemical reactions October 15th, 2018

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1 Study of ARO-ANG3 October 15th, 2018

180 Degree Capital Corp. Announces New Portfolio Holdings Airgain, Inc., EMCORE Corporation, Lantronix, Inc. and PDL BioPharma, Inc. October 12th, 2018

TUBALL single wall carbon nanotubes: No ecotoxicity found, unlike other carbon nanotubes October 12th, 2018

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

Big award enables study of small surfaces: Rice U.'s Matt Jones wins Packard Fellowship to view nanoscale chemical reactions October 15th, 2018

Graphene shows unique potential to exceed bandwidth demands of future telecommunications October 12th, 2018

High-performance self-assembled catalyst for SOFC October 12th, 2018

Tracking a Killer: UCSB, UCSD and SBP researchers trace the complex and variable pathways to the deadly condition known as sepsis October 12th, 2018

Tools

Big award enables study of small surfaces: Rice U.'s Matt Jones wins Packard Fellowship to view nanoscale chemical reactions October 15th, 2018

Nanometrics to Announce Third Quarter Financial Results on October 30, 2018 October 10th, 2018

UCI scientists push microscopy to sub-molecular resolution: Carbon monoxide used to measure electric forces in single chemical compound October 2nd, 2018

Carbon nanodots do an ultrafine job with in vitro lung tissue: New experiments highlight the role of charge and size when it comes to carbon nanodots that mimic the effect of nanoscale pollution particles on the human lung. September 12th, 2018

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