Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New security and medical sensor devices made possible by metallic nanostructures

09.04.2009
Scientists have designed tiny new sensor structures that could be used in novel security devices to detect poisons and explosives, or in highly sensitive medical sensors, according to research published yesterday (8 April) in Nano Letters.

The new 'nanosensors', which are based on a fundamental science discovery in UK, Belgian and US research groups, could be tailor-made to instantly detect the presence of particular molecules, for example poisons or explosives in transport screening situations, or proteins in patients' blood samples, with high sensitivity.

The researchers were led by Imperial College London physicists funded by the Engineering and Physical Sciences Research Council. The team showed that by putting together two specific 'nanostructures' made of gold or silver, they can make an early prototype device which, once optimised, should exhibit a highly sensitive ability to detect particular chemicals in the immediate surroundings.

The nanostructures are each about 500 times smaller than the width of a human hair. One is shaped like a flat circular disk while the other looks like a doughnut with a hole in the middle. When brought together they interact with light very differently to the way they behave on their own. The scientists have observed that when they are paired up they scatter some specific colours within white light much less, leading to an increased amount of light passing through the structure undisturbed. This is distinctly different to how both structures scatter light separately. This decrease in the interaction with light is in turn affected by the composition of molecules in close proximity to the structures. The researchers hope that this effect can be harnessed to produce sensor devices.

Lead researcher on the project Professor Stefan Maier from Imperial's Department of Physics, and an Associate of Imperial's Institute for Security Science and Technology, said:

"Pairing up these structures has a unique effect on the way they scatter light – an effect which could be very useful if, as our computer simulations suggest, it is extremely sensitive to changes in surrounding environment. With further testing we hope to show that it is possible to harness this property to make a highly sensitive nanosensor."

Metal nanostructures have been used as sensors before, as they interact very strongly with light due to so-called localised plasmon resonances. But this is the first time a pair with such a carefully tailored interaction with light has been created.

The device could be tailored to detect different chemicals by decorating the nanostructure surface with specific 'molecular traps' that bind the chosen target molecules. Once bound, the target molecules would change the colours that the device absorbs and scatters, alerting the sensor to their presence. The team's next step is to test whether the pair of nanostructures can detect chosen substances in lab experiments.

Professor Maier concludes: "This study is a beautiful example of how concepts from different areas of physics fertilise each other – in essence our nanosensor system is a classical analogue of electromagnetically induced transparency, a famous phenomenon from quantum mechanics."

Danielle Reeves | EurekAlert!
Further information:
http://www.imperial.ac.uk

More articles from Physics and Astronomy:

nachricht Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)

nachricht Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory

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: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>