Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Photonics: Deconstructed nanosensors light the way forward

14.02.2013
A flexible design approach for nanosensors that overcomes practicality and reliability issues is now available
Metal nanostructures can act as tiny antennae to control light since they can focus and guide light on the smallest of scales. The optical properties of these antennae depend strongly on their size and shape, making it difficult to predict which shape to choose for a desired optical effect without relying on complex theoretical calculations. Mohsen Rahmani and co-workers at the A*STAR Data Storage Institute, Singapore, and Imperial College London, UK, have now developed a method that allows for the practical and reliable design of these nano-antennae (1)

Their method is based on new understanding of the optical resonance properties of a few standardized building blocks of the antennae that arise from plasmons — the collective movements of electrons at their surface. “Our novel understanding captures aspects of device design that extend well beyond known optical interference mechanisms and significantly advances our understanding of the plasmonic resonance spectrum. This could bring about new applications,” explains Rahmani.

Some of the most useful properties of plasmonic antennae arise when the metal nanostructures are brought within close proximity to each other. This leads to interference effects near their surface that cause sharp spectral features, known as Fano resonances. Any changes near the nanostructures, such as the introduction of a few molecules or fluctuations in temperature, can impact the sensitive Fano resonances. These changes can be detected and used for sensing applications.

Typically, researchers iteratively use computer models of nanostructures to optimize the design of plasmonic antennae. Rahmani and co-workers simplified the approach by using standardized subunits of nanoparticles called plasmonic oligomers. For example, they deconstructed a cross-shaped structure, consisting of five dots, into two different subunits — one with three dots in a line and one with four outer dots. They then determined the plasmonic resonance of an entire array simply by combining those subunits.

By modeling the properties of the oligomers and comparing their results with measurements of optical spectra, Rahmani observed a systematic dependence of the optical resonances on individual subunits. The team’s findings suggest that the optical properties of various plasmonic antennae can be designed easily from just a few basic building blocks.

"The possible combinations are almost endless and these structures could find many applications," says Rahmani. These range from nanoscale lasers and optical switches for telecommunications to biosensing. “We are now going to develop these oligomers as nanosensing platforms for detecting the adsorption of chemical molecules and protein monolayers.”

The A*STAR-affiliated researchers contributing to this research are from the Data Storage Institute

Journal information

Rahmani, M., Lei, D. Y., Giannini, V., Lukiyanchuk, B., Ranjbar, M. et al. Subgroup decomposition of plasmonic resonances in hybrid oligomers: modeling the resonance lineshape. Nano Letters 12, 2101–2106 (2012).

A*STAR Research | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6626
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht A new stable form of plutonium discovered at the ESRF
21.10.2019 | European Synchrotron Radiation Facility

nachricht Double layer of graphene helps to control spin currents
18.10.2019 | University of Groningen

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Solving the mystery of quantum light in thin layers

A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)

It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...

Im Focus: An ultrafast glimpse of the photochemistry of the atmosphere

Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.

The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...

Im Focus: Shaping nanoparticles for improved quantum information technology

Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.

Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...

Im Focus: Novel Material for Shipbuilding

A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.

The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...

Im Focus: Controlling superconducting regions within an exotic metal

Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).

Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

NEXUS 2020: Relationships Between Architecture and Mathematics

02.10.2019 | Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

 
Latest News

Phagocytes versus killer cells - A closer look into the tumour tissue

21.10.2019 | Life Sciences

A new stable form of plutonium discovered at the ESRF

21.10.2019 | Physics and Astronomy

Candidate Ebola vaccine still effective when highly diluted, macaque study finds

21.10.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>