My watch list  

Nanoscale spectroscopy with optical antennas


Optical antennas made of gold nanoparticles can enhance the sensitivity of photoluminescence and vibrational spectroscopy, according to research published in Chemical Science.

In traditional microscopy and spectroscopy, components such as lenses, mirrors and diffractive elements are used to control and focus the optical radiation. This relies on the wave nature of the radiation and means the smallest volume to which the radiation can be localised, and so the technique’s sensitivity, is limited by diffraction.

Now Lukas Novotny and colleagues at the University of Rochester, USA, have taken inspiration from radio wave manipulation and designed an optical antenna that can boost the interaction between light and the particle being studied. The fluorescence of a single molecule can be enhanced by more than a factor of 10 using this technique. The optical antenna, which consists of a single colloidal gold nanoparticle on the end of a pointed dielectric fibre, replaces a conventional focusing lens or objective, so the incoming light can be focused to dimensions smaller than the diffraction limit.

As well as improving chemical and biological sensing, the technique holds promise for resolving open questions in surface enhanced Raman scattering and fluorescence, says Novotny.

Original publication: Palash Bharadwaj, Ryan Beams and Lukas Novotny, Chemical Science, 2010

More about Royal Society of Chemistry
More about University of Rochester
  • News

    Defects in atomically thin semiconductor emit single photons

    Researchers at the University of Rochester have shown that defects on an atomically thin semiconductor can produce light-emitting quantum dots. The quantum dots serve as a source of single photons and could be useful for the integration of quantum photonics with solid-state electronics - a ... more

    New self-stretching material developed

    Although most materials slightly expand when heated, there is a new class of rubber-like material that not only self-stretches upon cooling; it reverts back to its original shape when heated, all without physical manipulation. The findings were recently published in the journal ACS Macro Le ... more

    New laser-patterning technique turns metals into supermaterials

    By zapping ordinary metals with femtosecond laser pulses researchers from the University of Rochester in New York have created extraordinary new surfaces that efficiently absorb light, repel water and clean themselves. The multifunctional materials could find use in durable, low maintenance ... more

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE