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 Observations of nearby supernova and associated jet cocoon provide new insights on gamma-ray bursts
18.01.2019 | George Washington University

nachricht A new twist on a mesmerizing story
17.01.2019 | ETH Zurich Department of Physics

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: Ten-year anniversary of the Neumayer Station III

The scientific and political community alike stress the importance of German Antarctic research

Joint Press Release from the BMBF and AWI

The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...

Im Focus: Ultra ultrasound to transform new tech

World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles

The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Additive manufacturing reflects fundamental metallurgical principles to create materials

18.01.2019 | Materials Sciences

How molecules teeter in a laser field

18.01.2019 | Life Sciences

The cytoskeleton of neurons has been found to be involved in Alzheimer's disease

18.01.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>