Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Good vibrations help reveal molecular details: Rice University scientists combine disciplines to pinpoint small structures in unlabeled molecules

The molecules tryptophan, left, and decyltrimethylammonium bromide, right, over their SABERS maps. SABERS, a new analysis method developed at Rice University, is able to obtain structural details of molecules in lipid membranes near gold nanoparticles without molecular tags. Credit: Hafner Lab/Rice University
The molecules tryptophan, left, and decyltrimethylammonium bromide, right, over their SABERS maps. SABERS, a new analysis method developed at Rice University, is able to obtain structural details of molecules in lipid membranes near gold nanoparticles without molecular tags.

Credit: Hafner Lab/Rice University

Abstract:
Five years of hard work and a little "cosmic luck" led Rice University researchers to a new method to obtain structural details on molecules in biomembranes.

Good vibrations help reveal molecular details: Rice University scientists combine disciplines to pinpoint small structures in unlabeled molecules

Houston, TX | Posted on February 15th, 2017

The method by the Rice lab of physicist Jason Hafner combines experimental and computational techniques and relies on the plasmonic properties of gold nanoparticles. It takes advantage of the nanoparticles' unique ability to focus light on very small targets.

The researchers call their protocol SABERS, for structural analysis by enhanced Raman scattering, and say it could help scientists who study amyloid interactions implicated in neurodegenerative disease, the neuroprotective actions of fatty acids and the function of chemotherapy agents.

The details appear this month in the American Chemical Society journal Nano Letters.

Their method extracts the location of specific chemical groups within the molecules by locating their characteristic vibrations. When a laser activates plasmons in the nanoparticles, it amplifies vibrationally scattered light from nearby molecules, a phenomenon called surface-enhanced Raman scattering (SERS). The enhancement is sensitive to exactly where the molecule sits relative to the nanoparticle.

"Molecules can vibrate in many different ways, so we have to assign a 'center of vibration' to each one," Hafner said. "If you watch some part of a molecule vibrating, you can visualize where it occurs, but we also had to find a mathematical way to describe it."

SERS spectra are notoriously difficult to untangle, so the full SABERS method also requires unenhanced spectral measurements and theoretical calculations of both the nanorod optics and the molecular properties, he said.

Hafner and his team tested their technique on three structures: surfactant molecules that come with gold nanorods, lipid molecules that form membranes on gold nanorods and tryptophan, an amino acid that settles into the membrane.

"We found that the surfactant layer is tilted by 25 degrees, which is interesting because it explains why other measurements found that the layer appears thinner than expected," Hafner said.

Lipids easily replace surfactants on nanorods since they end in the same chemical structure. By comparing vibrations of that structure in the lipid headgroup to a double bond in the tail, SABERS found the correct orientation and thickness of the lipid bilayer membrane. "It's just cosmic luck that a lipid ends in a perfectly symmetric structure that vibrates and is Raman active and loves to sit on a nanorod," Hafner said.

The researchers also used SABERS to locate tryptophan in the lipid bilayer. "It's very bright, spectroscopically, and easy to see," he said. "In real biological structures, tryptophan is just a small residue attached to a much larger protein. However, tryptophan helps anchor the protein to the membrane, so researchers want to know where it prefers to sit."

Next, Hafner wants to analyze bigger molecules. "In principle, through spectroscopic tricks, we could take this to larger structures, and perhaps even find every residue in a protein to get the whole structure. That's futuristic, but it's where we think we can go with it," he said.

Rice alumnus James Matthews, now a software engineer at Schlumberger, is lead author of the paper. Co-authors are Rice undergraduate students Cyna Shirazinejad and Grace Isakson and graduate student Steven Demers. Hafner is a professor of physics and astronomy and of chemistry.

The Robert A. Welch Foundation and Lockheed Martin supported the research.

####

About Rice University
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,879 undergraduates and 2,861 graduate students, Rice’s undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for happiest students and for lots of race/class interaction by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger’s Personal Finance. To read “What they’re saying about Rice,” go to http://tinyurl.com/RiceUniversityoverview .

Follow Rice News and Media Relations via Twitter @RiceUNews

For more information, please click here

Contacts:
Jeff Falk
713-348-6775


Mike Williams
713-348-6728

Copyright © Rice University

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

Read the abstract at:

Hafner Lab:

Rice Physics and Astronomy Department:

Wiess School of Natural Sciences:

Related News Press

News and information

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Leti to Demo 1st Wireless UNB Transceiver for ‘Massive Internet of Things’ at RFIC 2017 and IMS 2017: Leti Will also Present Three Papers & Two Workshops on 5G Communications IC Design, from RF to mm-Wave, During IMS 2017 and RFIC 2017 in Hawaii May 24th, 2017

GLOBALFOUNDRIES and Chengdu Partner to Expand FD-SOI Ecosystem in China: More than $100M investment to establish a center of excellence for FDXTM FD-SOI design May 23rd, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Cancer

Mayo Clinic researchers develop new tumor-shrinking nanoparticle to fight cancer, prevent recurrence May 1st, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

Nanopores could map small changes in DNA that signal big shifts in cancer April 13th, 2017

Keystone Nano Announces Start Of Clinical Testing Of Ceramide Nanoliposome For The Improved Treatment Of Cancer April 11th, 2017

Govt.-Legislation/Regulation/Funding/Policy

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Graphene-nanotube hybrid boosts lithium metal batteries: Rice University prototypes store 3 times the energy of lithium-ion batteries May 19th, 2017

Stanford scientists use nanotechnology to boost the performance of key industrial catalyst May 18th, 2017

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

Possible Futures

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

GLOBALFOUNDRIES and Chengdu Partner to Expand FD-SOI Ecosystem in China: More than $100M investment to establish a center of excellence for FDXTM FD-SOI design May 23rd, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Leti Will Demo World’s-first WVGA 10-µm Pitch GaN Microdisplays for Augmented Reality Video at Display Week in Los Angles: Invited Paper also Will Present Leti’s Success with New Augmented Reality Technology That Reduces Pixel Pitch to Less than 5 Microns May 22nd, 2017

Nanomedicine

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Sensors detect disease markers in breath May 19th, 2017

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

The brighter side of twisted polymers: Conjugated polymers designed with a twist produce tiny, brightly fluorescent particles with broad applications May 16th, 2017

Discoveries

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Sensors detect disease markers in breath May 19th, 2017

Graphene-nanotube hybrid boosts lithium metal batteries: Rice University prototypes store 3 times the energy of lithium-ion batteries May 19th, 2017

Announcements

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Leti to Demo 1st Wireless UNB Transceiver for ‘Massive Internet of Things’ at RFIC 2017 and IMS 2017: Leti Will also Present Three Papers & Two Workshops on 5G Communications IC Design, from RF to mm-Wave, During IMS 2017 and RFIC 2017 in Hawaii May 24th, 2017

GLOBALFOUNDRIES and Chengdu Partner to Expand FD-SOI Ecosystem in China: More than $100M investment to establish a center of excellence for FDXTM FD-SOI design May 23rd, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

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

Three-dimensional graphene: Experiment at BESSY II shows that optical properties are tuneable May 24th, 2017

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Sensors detect disease markers in breath May 19th, 2017

Graphene-nanotube hybrid boosts lithium metal batteries: Rice University prototypes store 3 times the energy of lithium-ion batteries May 19th, 2017

Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Gas gives laser-induced graphene super properties: Rice University study shows inexpensive material can be superhydrophilic or superhydrophobic May 15th, 2017

Fed grant backs nanofiber development: Rice University joins Department of Energy 'Next Generation Machines' initiative May 10th, 2017

'Hot' electrons don't mind the gap: Rice University scientists find nanogaps in plasmonic gold wires enhance voltage when excited May 8th, 2017

Nanobiotechnology

Zap! Graphene is bad news for bacteria: Rice, Ben-Gurion universities show laser-induced graphene kills bacteria, resists biofouling May 22nd, 2017

Sensors detect disease markers in breath May 19th, 2017

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

The brighter side of twisted polymers: Conjugated polymers designed with a twist produce tiny, brightly fluorescent particles with broad applications May 16th, 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