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
Scientists in Switzerland have developed a protective coating for seeds that poisons pests with cyanide when they bite into it.
The coating is a system of two layers and only becomes toxic when the layers are mixed, eliminating the problem of environmental contamination that is associated w ... more
Scientists in France have produced hematite using a bacterial pathway for use as an electrode material in Li-ion technologies.
Currently, most commercial electrode materials for Li-ion technologies are prepared using the ceramic method, which requires long heating periods at high temperatur ... more
An international research team has shown that that the power conversion efficiency of sea tangle extract is comparable to platinum in solar cell electrodes.
Dye-sensitized solar cells (DSCs) are quickly becoming a widespread and affordable alternative to photovoltaic solar cells. The electr ... more
The 12th International Symposium on Macrocyclic and Supramolecular Chemistry will be run in 2017 in conjunction with the Royal Society of Chemistry's biennial ISACS: Challenges in Organic Materials & Supramolecular Chemistry meeting and will take place in Cambridge. The conference themes wi ... more
The RSC Applied Catalysis Group and the SCI Fine Chemicals Group are pleased to announce ‘Challenges in Catalysis V’, returning by popular demand, following highly successful meetings in 2007, 2009, 2011, and 2014. Once again, an exciting programme has been assembled to highlight the curren ... more
The aim of this Faraday Discussion is to bring together researchers from the chemical sciences community who are working on new potential carbon capture materials and processes, physical properties of CO2 and gas mixtures, and carbon dioxide utilisation with researchers from energy and proc ... more
The RSC is a leading international publisher of highly regarded journals and books in the chemical sciences. The RSC is also the professional body for chemists with a global membership of over 46,000. more
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
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
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