Such highly coveted technical capabilities as the observation of single catalytic processes in nanoreactors, or the optical detection of low concentrations of biochemical agents and gases are an important step closer to fruition. Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab), in collaboration with researchers at the University of Stuttgart in Germany, report the first experimental demonstration of antenna-enhanced gas sensing at the single particle level. By placing a palladium nanoparticle on the focusing tip of a gold nanoantenna, they were able to clearly detect changes in the palladium's optical properties upon exposure to hydrogen.
"We have demonstrated resonant antenna-enhanced single-particle hydrogen sensing in the visible region and presented a fabrication approach to the positioning of a single palladium nanoparticle in the nanofocus of a gold nanoantenna," says Paul Alivisatos, Berkeley Lab's director and the leader of this research. "Our concept provides a general blueprint for amplifying plasmonic sensing signals at the single-particle level and should pave the road for the optical observation of chemical reactions and catalytic activities in nanoreactors, and for local biosensing."
Alivisatos, who is also the Larry and Diane Bock Professor of Nanotechnology at the University of California, Berkeley, is the corresponding author of a paper in the journal Nature Materials describing this research. The paper is titled "Nanoantenna-enhanced gas sensing in a single tailored nanofocus." Co-authoring the paper with Alivisatos were Laura Na Liu, Ming Tang, Mario Hentschel and Harald Giessen.
One of the hottest new fields in technology today is plasmonics the confinement of electromagnetic waves in dimensions smaller than half-the-wavelength of the incident photons in free space. Typically this is done at the interface between metallic nanostructures,
|Contact: Lynn Yarris|
DOE/Lawrence Berkeley National Laboratory