Navigation Links
Study shows nanoshells ideal as chemical nanosensors

'Nanoshells' enhance sensitivity to chemical detection by factor of 10 billion New research published in the Proceedings of the National Academy of Science finds that tailored nanoparticles known as nanoshells can enhance chemical sensing by as much as 10 billion times. That makes them about 10,000 times more effective at Raman scattering than traditional methods.

When molecules and materials scatter light, a small fraction of the light interacts in such a way that it allows scientists to determine their detailed chemical makeup. This property, known as Raman scattering, is used by medical researchers, drug designers, chemists and other scientists to determine what materials are made of. An enormous limitation in the use of Raman scattering has been its extremely weak sensitivity. While it was discovered almost three decades ago that roughened metallic surfaces could enhance Raman scattering signals by factors of 1 million, this "surface-enhancement" effect has been difficult to control, predict, and reproduce for practical sensing applications. Now, Rice researchers have shown that nanoshells can provide large, clean, reproducible enhancements of this effect, opening the door for new, all-optical sensing applications. "Not only did we find that nanoshells are extremely effective at magnifying the Raman signature of molecules, we found each individual nanoshell acts as an independent Raman enhancer," said lead researcher Naomi Halas, the Stanley C. Moore Professor of Electrical and Computer Engineering, Professor of Chemistry and Director of Rice's Laboratory of Nanophotonics. "That creates an opportunity to design all-optical nanoscale sensors -- essentially new molecular-level diagnostic instruments -- that could detect as little as a few molecules of a target substance, which could be anything from a drug molecule or a key disease protein to a deadly chemical agent." About 1/20th the size of a red blood cell, nanoshells are about the size of a virus. They are ball-shaped and consist of a core of non-conducting glass that is covered by a metallic shell, typically either gold or silver. The metal shell "captures" passing light and focuses it, a property that directly leads to the enormous Raman enhancements observed. Furthermore, nanoshells can be "tuned" to interact with specific wavelengths of light by varying the thickness of their shells. This tunability allows for the Raman enhancements to be optimized for specific wavelengths of light. Discovered by Halas at Rice in the 1990s, nanoshells are already being developed for applications including cancer diagnosis, cancer therapy, diagnosis and testing for proteins associated with Alzheimer's disease, drug delivery and rapid whole-blood immunoassay. In the current study, Halas and former graduate student Joseph B. Jackson, now with Nanospectra Biosciences, Inc., created thin films of nanoshells deposited atop plates of glass. Films with various densities were studied, as were films containing both silver and gold nanoshells. Through painstaking analysis, Halas and Jackson showed that the nanoshells' 10 billion-fold increase in Raman effect was due entirely to the interactions of light with individual nanoshells. This is markedly different from the pattern exhibited by pure gold or silver nanoparticle films. In that case, the Raman enhancement is an aggregate effect, due to the presence of localized "junctions" or "hot spots" between metallic regions of the metallic film substrate. The finding that individual nanoshells can vastly enhance the Raman effect opens the door for biosensor designs that use a single nanoshell, something that could prove useful for engineers who are trying to probe the chemical processes within small structures such as individual cells, or for the detection of very small amounts of a material, like a few molecules of a deadly biological or chemical agent.
'"/>

Source:Eurekalert


Related biology news :

1. Novel Asthma Study Shows Multiple Genetic Input Required; Single-gene Solution Shot Down
2. Emory Study Tests Bone Marrow Stem Cells to Improve Circulation in Legs
3. UCLA Study Shows One-Third of Drug Ads in Medical Journals Do Not Contain References Supporting Medical Claims
4. Study Demonstrates Gene Expression Microarrays are Comparable and Reproducible
5. Study Links Ebola Outbreaks To Animal Carcasses
6. Breakthrough Microarray-based Technology for the Study of Cancer
7. NYU Study Reveals How Brains Immune System Fights Viral Encephalitis
8. Study finds more than one-third of human genome regulated by RNA
9. Leukemia Drug Breakthrough Study In New England Journal Of Medicine
10. Study identifies predictors of HIV drug resistance in patients beginning triple therapy
11. New Study from Affymetrix Laboratories Points to Changing View of How Genome Works

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/4/2017)... 4, 2017   EyeLock LLC , a leader ... United States Patent and Trademark Office (USPTO) has issued ... linking of an iris image with a face image ... the company,s 45 th issued patent. ... timely given the multi-modal biometric capabilities that have recently ...
(Date:3/30/2017)... 2017  On April 6-7, 2017, Sequencing.com will host ... hackathon at Microsoft,s headquarters in Redmond, ... on developing health and wellness apps that provide a ... Genome is the first hackathon for personal genomics ... companies in the genomics, tech and health industries are ...
(Date:3/30/2017)... , March 30, 2017 Trends, opportunities ... (physiological and behavioral), by technology (fingerprint, AFIS, iris recognition, ... recognition, and others), by end use industry (government and ... immigration, financial and banking, and others), and by region ... , Asia Pacific , and ...
Breaking Biology News(10 mins):
(Date:5/23/2017)... (PRWEB) , ... May 22, 2017 , ... ... year in a row in the Aragon Research Globe™ for Corporate Learning, 2017. ... with industry direction and market demand, and effectively perform against those strategies. NetDimensions’ ...
(Date:5/23/2017)... ... May 23, 2017 , ... Vortex Biosciences , provider of circulating ... prostate circulating tumor cells using Vortex microfluidic technology ” in Nature Precision Oncology on ... Dr. Dino Di Carlo and Dr. Matthew Rettig at the University of California, Los ...
(Date:5/23/2017)... ... May 23, 2017 , ... Kathy Goin ... of Clinical Operations. She brings years of expertise in establishing and leading clinical ... foundation as a licensed occupational therapist, through a variety of leadership roles in ...
(Date:5/23/2017)... ... 2017 , ... Cambridge Semantics , the leading provider of Big Data ... Conference and Expo in Boston May 23-25 with a featured speaker and solution ... Data Lake is also a finalist for the Best of Show award. , James ...
Breaking Biology Technology: