Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International

Wikipedia Affiliate Button

Home > Press > Rice U. lab probes molecular limit of plasmonics: Optical effect detailed in organic molecules with fewer than 50 atoms

Naomi Halas is the Stanley C. Moore Professor of Electrical and Computer Engineering and professor of chemistry, bioengineering, physics and astronomy, and materials science and nanoengineering at Rice University. (Photo by Jeff Fitlow/Rice University)
Naomi Halas is the Stanley C. Moore Professor of Electrical and Computer Engineering and professor of chemistry, bioengineering, physics and astronomy, and materials science and nanoengineering at Rice University. (Photo by Jeff Fitlow/Rice University)

Abstract:
Rice University researchers are probing the physical limits of excited electronic states called plasmons by studying them in organic molecules with fewer than 50 atoms.

Rice U. lab probes molecular limit of plasmonics: Optical effect detailed in organic molecules with fewer than 50 atoms

Houston, TX | Posted on September 5th, 2018

Plasmons are oscillations in the plasma of free electrons that constantly swirl across the surface of conductive materials like metals. In some nanomaterials, a specific color of light can resonate with the plasma and cause the electrons inside it to lose their individual identities and move as one, in rhythmic waves. Rice's Laboratory for Nanophotonics (LANP) has pioneered a growing list of plasmonic technologies for applications as diverse as color-changing glass, molecular sensing, cancer diagnosis and treatment, optoelectronics, solar energy collection and photocatalysis.

Reporting online in the Proceedings of the National Academy of Sciences, LANP scientists detailed the results of a two-year experimental and theoretical study of plasmons in three different polycyclic aromatic hydrocarbons (PAHs). Unlike the plasmons in relatively large metal nanoparticles, which can typically be described with classical electromagnetic theory like Maxwell's equations, the paucity of atoms in the PAHs produces plasmons that can only be understood in terms of quantum mechanics, said study co-author and co-designer Naomi Halas, the director of LANP and the lead researcher on the project.

"These PAHs are essentially scraps of graphene that contain five or six fused benzene rings surrounded by a perimeter of hydrogen atoms," Halas said. "There are so few atoms in each that adding or removing even a single electron dramatically changes their electronic behavior."

Halas' team had experimentally verified the existence of molecular plasmons in several previous studies. But an investigation that combined side by side theoretical and experimental perspectives was needed, said study co-author Luca Bursi, a postdoctoral research associate and theoretical physicist in the research group of study co-designer and co-author Peter Nordlander.

"Molecular excitations are a ubiquity in nature and very well studied, especially for neutral PAHs, which have been considered as the standard of non-plasmonic excitations in the past," Bursi said. "Given how much is already known about PAHs, they were an ideal choice for further investigation of the properties of plasmonic excitations in systems as small as actual molecules, which represent a frontier of plasmonics."

Lead co-author Kyle Chapkin, a Ph.D. student in applied physics in the Halas research group, said, "Molecular plasmonics is a new area at the interface between plasmonics and molecular chemistry, which is rapidly evolving. When plasmonics reach the molecular scale, we lose any sharp distinction of what constitutes a plasmon and what doesn't. We need to find a new rationale to explain this regime, which was one of the main motivations for this study."

In their native state, the PAHs that were studied -- anthanthrene, benzo[ghi]perylene and perylene -- are charge-neutral and cannot be excited into a plasmonic state by the visible wavelengths of light used in Chapkin's experiments. In their anionic form, the molecules contain an additional electron, which alters their "ground state" and makes them plasmonically active in the visible spectrum. By exciting both the native and anionic forms of the molecules and comparing precisely how they behaved as they relaxed back to their ground states, Chapkin and Bursi built a solid case that the anionic forms do support molecular plasmons in the visible spectrum.

The key, Chapkin said, was identifying a number of similarities between the behavior of known plasmonic particles and the anionic PAHs. By matching both the timescales and modes for relaxation behaviors, the LANP team built up a picture of a characteristic dynamics of low-energy plasmonic excitations in the anionic PAHs.

"In molecules, all excitations are molecular excitations, but select excited states show some characteristics that allow us to draw a parallel with the well-established plasmonic excitations in metal nanostructures," Bursi said.

"This study offers a window on the sometimes surprising behavior of collective excitations in few-atom quantum systems," Halas said. "What we've learned here will aid our lab and others in developing quantum-plasmonic approaches for ultrafast color-changing glass, molecular-scale optoelectronics and nonlinear plasmon-mediated optics."

Halas is Rice's Stanley C. Moore Professor of Electrical and Computer Engineering and professor of chemistry, bioengineering, physics and astronomy, and materials science and nanoengineering. Nordlander is professor of physics and astronomy, electrical and computer engineering, and materials science and nanoengineering.

Additional study co-authors include Grant Stec, Adam Lauchner, Nathaniel Hogan and Yao Cui, all of Rice. This research was funded by the Robert A. Welch Foundation.

-

####

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 3,970 undergraduates and 2,934 graduate students, Rice’s undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 2 for quality of life 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:
David Ruth
713-348-6327


Jade Boyd
713-348-6778

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

The DOI of the PNAS paper is: 10.1073/pnas.1805357115

Related News Press

News and information

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Cancer

With nanopore sensing, VCU physics researchers detect subtle changes in single particles: The researchers' findings 'open the door to observe all kinds of interesting phenomenon on nanosurfaces,' an area of great interest to chemists February 21st, 2019

Platinum nanoparticles for selective treatment of liver cancer cells February 21st, 2019

What happens to magnetic nanoparticles once in cells? February 21st, 2019

Fighting cancer: Scientists developed a theory of 'collective behavior' of nanoparticles: Experiments with supercomputers are led by Russian and Scottish scientists February 1st, 2019

Ultra-sensitive sensor with gold nanoparticle array January 9th, 2019

Plasmonics

Rice U. lab adds porous envelope to aluminum plasmonics: Scientists marry gas-trapping framework to light-powered nanocatalysts February 10th, 2019

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Possible Futures

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Chip Technology

Exotic “second sound” phenomenon observed in pencil lead: At relatively balmy temperatures, heat behaves like sound when moving through graphite, study reports March 15th, 2019

Pushing Past Limits: Junkai Jiang receives prestigious Ph.D. Student Fellowship from IEEE Electron Devices Society March 14th, 2019

Nanometrics Announces $80 Million Share Repurchase Program March 14th, 2019

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

Nanomedicine

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

Arrowhead Pharmaceuticals Begins Dosing in Phase 1 Study of ARO-APOC3 for Treatment of Hypertriglyceridemia March 11th, 2019

New optical imaging system could be deployed to find tiny tumors: Near-infrared technology pinpoints fluorescent probes deep within living tissue; may be used to detect cancer earlier March 8th, 2019

Computer-designed vaccine elicits potent antibodies against RSV: The nanoparticle platform for this respiratory syncytial virus study will be applied to vaccine research on flu, HIV, and more; Seattle startup Icosavax will advance related clinical trials March 8th, 2019

Optical computing/Photonic computing

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

New blueprint for understanding, predicting and optimizing complex nanoparticles: Guidelines have the potential to transform the fields of optoelectronics, bio-imaging and energy harvesting March 1st, 2019

Hall effect becomes viscous in graphene: Researchers at the University of Manchester in the UK have discovered that electrons in graphene act like a very unique liquid February 28th, 2019

Researchers move closer to practical photonic quantum computing: New method fills critical need to measure large-scale quantum correlation of single photons February 28th, 2019

Sensors

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

Quantum sensing method measures minuscule magnetic fields: MIT researchers find a new way to make nanoscale measurements of fields in more than one dimension March 15th, 2019

Oxford Instruments and partners launch EU Horizon 2020 project ULISSES: Air sensors for everyone, everywhere March 7th, 2019

Nanoelectronics

When semiconductors stick together, materials go quantum: A new study led by Berkeley Lab reveals how aligned layers of atomically thin semiconductors can yield an exotic new quantum material March 12th, 2019

Zips on the nanoscale: New method of synthesising nanographene on metal oxide surfaces March 5th, 2019

Large, stable pieces of graphene produced with unique edge pattern: Breakthrough in graphene research February 1st, 2019

Kiel physicists discover new effect in the interaction of plasmas with solids January 18th, 2019

Discoveries

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Announcements

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

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

Gold nanoparticles to facilitate in-situ detection of amplified DNA at room temperature March 21st, 2019

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

New method to reduce uranium concentration in contaminated water March 18th, 2019

Converting biomass by applying mechanical force Nanoscientists discover new mechanism to cleave cellulose effectively and in an environmentally friendly way March 15th, 2019

Energy

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

Layering titanium oxide's different mineral forms for better solar cells: Kanazawa University-led researchers layer two different mineral forms of titanium oxide to improve electron flow at the negative electrode for better metal halide perovskite-type solar cells March 2nd, 2019

New blueprint for understanding, predicting and optimizing complex nanoparticles: Guidelines have the potential to transform the fields of optoelectronics, bio-imaging and energy harvesting March 1st, 2019

Avoiding the Crack of Doom: New imaging technique reveals how mechanical damage begins at the molecular scale February 25th, 2019

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

Fish-Inspired Material Changes Color Using Nanocolumns March 18th, 2019

Quantum sensing method measures minuscule magnetic fields: MIT researchers find a new way to make nanoscale measurements of fields in more than one dimension March 15th, 2019

Researchers reverse the flow of time on IBM's quantum computer March 14th, 2019

Pushing Past Limits: Junkai Jiang receives prestigious Ph.D. Student Fellowship from IEEE Electron Devices Society March 14th, 2019

Photonics/Optics/Lasers

CEA-Leti Announces Prototype of Next-generation Photo-Acoustic Sensors for Gas Detection: REDFINCH Team Achieves These Capabilities in Mid-infrared Region, Where Many Important Chemical and Biological Species Have Strong Absorption Fingerprints March 21st, 2019

New blueprint for understanding, predicting and optimizing complex nanoparticles: Guidelines have the potential to transform the fields of optoelectronics, bio-imaging and energy harvesting March 1st, 2019

Hybrid material may outperform graphene in several applications: A structure comprising a molybdenum disulfide monolayer on an azobenzene substrate could be used to build a highly compactable and malleable quasi-two-dimensional transistor powered by light February 28th, 2019

Researchers move closer to practical photonic quantum computing: New method fills critical need to measure large-scale quantum correlation of single photons February 28th, 2019

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