Plasmonics: From metallic foils to cancer treatment

January 11, 2011
SEM images of nanoparticles fabricated for SERS by electron-beam lithography.

In a timely review paper, scientists from Japan, Germany, and Spain provide a highly relevant overview of the history, physical interpretation and applications of plasmons in metallic nanostructures.

Tadaaki Nagao at the International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) and colleagues in Germany and Spain present a review on plasmons in metallic . The article is published this week in the journal Science and Technology of .

The authors provide an extensive overview of the properties of plasmons in nanomaterials with emphasis on pioneering work of Ruthemann and Lang on electron energy loss spectroscopy (EELS) of in thin metal foils; recent infrared analysis of nanoscale metallic nanorods and nanoislands produced by ‘top-down’ photolithography; and the potential of metallic atomic wires for supporting plasmonic resonating modes. The review includes detailed explanations of plasmons for in vivo biosensing and nanoantennas.

A plasmon can be visualized as a collective oscillation of electronic ‘liquid’ in metals, similar to waves in lake, which are collective mode of the water molecules. Furthermore, surface plasmons are such oscillations confined to the surfaces of metals, which display a strong interaction with light, leading to the formation of so-called ‘polaritons’. Futuristic applications of plasmons include ideal lenses and even invisibility cloaks.

Research in the 1940s by Ruthemann and Lang on electrons flowing in thin metal foils using EELS yielded the first experimental sign of the presence of the theoretically predicted ‘plasma oscillations’ in metals. In 1957 Richie and colleagues predicted the existence of ‘surface localized’ plasmons, which was confirmed by Powell and Swan by EELS a few years later. In the 1960s researchers determined optical dispersion curves using optical spectroscopy, thereby opening up the possibility of optical applications of plasmon structures.

Illustration of multiplex cancer targeting by SERS nanoparticles encoded by Raman molecules and cancer antibodies.

In this review, Nagao and colleagues offer insights into optical applications of localized surface plasmons in structures produced by photolithography. Specific examples include metallic nanoantenna detectors—where resonant excitation of light leads to ultrahigh electromagnetic field enhancement owing to plasmon polaritons localized at the surface of nanostructures; and optical interactions between arrays of nanorods for ‘surface enhanced Raman scattering’, which shows potential for in vivo biomolecular sensing. The authors also describe the fabrication of a prototype random-nanogap antenna for enhanced IR spectroscopy and in situ spectral monitoring of surface enhancement of infrared absorption during film growth.

Furthermore, the authors describe new trends in plasmonics research, in particular observation of plasmonic resonant modes in indium nanowires grown in ultrahigh vacuum on stepped silicon substrates. They predict that these nanowires will be used as building blocks for developing plasmonic devices of the future.

This review includes 86 references and 12 figures, providing an invaluable source of up-to-date information for newcomers and experts in this exciting field of research.

Explore further: 'Light on a chip' potential seen by scientists spoofing natural phenomenon

More information: Tadaaki Nagao et al. Plasmons in nanoscale and atomic-scale system, Sci. Technol. Adv. Mater. Vol. 11 (2010) p. 054506. doi: 10.1088/1468-6996/11/5/054506

Related Stories

Going plasmonic in search of faster computing, communications

October 16, 2009

( -- A team of European researchers has demonstrated some of the first commercially viable plasmonic devices, paving the way for a new era of high-speed communications and computing in which electronic and optical ...

Graphene: What projections and humps can be good for

April 19, 2010

At present, graphene probably is the most investigated new material system worldwide. Due to its astonishing mechanical, chemical and electronic properties, it promises manifold future applications - for example in microelectronics. ...

Securing the nation with fingerprinting materials

November 9, 2010

Lawrence Livermore National Laboratory researchers may have found a way to improve Raman spectroscopy as a tool for identifying substances in extremely low concentrations. Potential applications for Raman spectroscopy include ...

Recommended for you

Physicists develop new technique to fathom 'smart' materials

November 26, 2015

Physicists from the FOM Foundation and Leiden University have found a way to better understand the properties of manmade 'smart' materials. Their method reveals how stacked layers in such a material work together to bring ...

Mathematicians identify limits to heat flow at the nanoscale

November 24, 2015

How much heat can two bodies exchange without touching? For over a century, scientists have been able to answer this question for virtually any pair of objects in the macroscopic world, from the rate at which a campfire can ...

New sensor sends electronic signal when estrogen is detected

November 24, 2015

Estrogen is a tiny molecule, but it can have big effects on humans and other animals. Estrogen is one of the main hormones that regulates the female reproductive system - it can be monitored to track human fertility and is ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.