Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Photonics: Deconstructed nanosensors light the way forward

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:

More articles from Physics and Astronomy:

nachricht First results of NSTX-U research operations
26.10.2016 | DOE/Princeton Plasma Physics Laboratory

nachricht Scientists discover particles similar to Majorana fermions
25.10.2016 | Chinese Academy of Sciences Headquarters

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: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>