Technical Feature

Technical Feature

Shape-Controlled Synthesis and Surface Plasmonic Properties of Metallic Nanostructures

Younan Xia and Naomi J. Halas

Abstract

The interaction of light with free electrons in a gold or silver nanostructure can give rise to collective excitations commonly known as surface plasmons. Plasmons provide a powerful means of confining light to metal/dielectric interfaces, which in turn can generate intense local electromagnetic fields and significantly amplify the signal derived from analytical techniques that rely on light, such as Raman scattering. With plasmons, photonic signals can be manipulated on the nanoscale, enabling integration with electronics (which is now moving into the nano regime). However, to benefit from their interesting plasmonic properties, metal structures of controlled shape (and size) must be fabricated on the nanoscale. This issue of MRS Bulletin examines how gold and silver nanostructures can be prepared with controllable shapes to tailor their surface plasmon resonances and highlights some of the unique applications that result, including enhancement of electromagnetic fields, optical imaging, light transmission, colorimetric sensing, and nanoscale waveguiding.

Keywords

  • field enhancement;
  • gold nanoparticles;
  • metallic nanostructures;
  • shape-controlled synthesis, silver nanoparticles;
  • surface plasmons

Younan Xia, Guest Editor for this issue of MRS Bulletin, is a professor of chemistry at the University of Washington. He received his BS degree in chemical physics from the University of Science and Technology of China (USTC) in 1987 and then worked as a graduate student on inorganic nonlinear optical crystals at the Fujian Institute of Research on the Structure of Matter, Academia Sinica. He earned his MS degree in inorganic chemistry from the University of Pennsylvania (with Alan G. MacDiarmid) in 1993 and his PhD degree in physical chemistry from Harvard University (with George M. Whitesides) in 1996. He then stayed at Harvard and worked as a postdoctoral fellow with both Whitesides and Mara Prentiss. He began as an assistant professor of chemistry at the University of Washington in 1997.

Xia's research interests include nanostructured materials, self-assembly, photonic crystals, colloidal chemistry, microfabrication, surface modification, electrospinning, conducting polymers, microfluidics, and novel devices for photonics, optoelectronics, and displays.

He has received many awards, including a National Science Foundation CAREER Award, the Camille Dreyfus Teacher–Scholar Award, and the Victor K. LaMer Award from the American Chemical Society. He has been an Alfred P. Sloan Research Fellow and a David and Lucile Packard Fellow. Xia is the co-author of more than 200 peer-reviewed publications and has edited a number of special issues and books on nanostructured materials. He currently serves as an associate editor for Nano Letters.

Xia can be reached by e-mail at xia@chem. washington.edu.

Naomi J. Halas, Guest Editor for this issue of MRS Bulletin, is the Stanley C. Moore Professor of Electrical and Computer Engineering and a professor of chemistry at Rice University. She received her undergraduate degree in chemistry from La Salle University in Philadelphia, and her MS and PhD degrees in physics from Bryn Mawr College, the latter while she was a graduate fellow at IBM's T.J. Watson Research Center. Following her postdoctoral research at AT&T Bell Laboratories, she joined the faculty at Rice. She is best known for her invention of nanoshells, a new type of nanoparticle with tunable optical properties especially suited for biotechnology applications. She has been honored with the NSF Young Investigator Award, three Hershel Rich Invention Awards, the 2003 Cancer Innovator Award from the Congressionally Directed Medical Research Programs of the Department of Defense, and the 2000 CRS–Cygnus Award for Outstanding Work in Drug Delivery. She was also awarded “Best Discovery of 2003” by Nanotechnology Now and was a finalist for the Small Times 2004 Nanotechnology Researcher of the Year. She has published more than 100 peer-reviewed papers, has presented over 150 invited talks, and holds nine issued patents. Halas is a fellow of the American Physical Society and of the Optical Society of America. She is also the founder and director of the Rice University Laboratory for Nanophotonics (LANP), a multidisciplinary research network whose mission is the design, invention, and application of nanoscale optical components.

Halas can be reached by e-mail at halas@rice.edu.

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