13-Jul-2017 - Osaka University

Signature analysis of single molecules using their noise signals

Noise is low-frequency random fluctuation that occurs in many systems, including electronics, environments, and organisms. Noise can obscure signals, so it is often removed from electronics and radio transmissions. The origin of noise in nanoscale electronics is currently of much interest, and devices that operate using noise have been proposed. Materials with a high surface-to-volume ratio are attractive for studying the noise produced by nanoscale electronics because they are very sensitive to changes of their surfaces. A representative material of this type is carbon nanotubes, which are rolled sheets of the graphene hexagonal network, which is only one carbon atom thick.

A Japanese collaboration led by Osaka University has explored the ability of single molecules to affect the noise generated by carbon nanotube-based nanoscale electronic devices. The team fabricated simple devices consisting of a carbon nanotube bridging two electrodes. The devices were exposed to different large molecules, causing some to bind to the carbon nanotube surface. It was found that different molecules gave unique noise signals related to the properties of the molecules. The strength of the interaction between the carbon nanotubes and molecules was able to be predicted from the obtained noise signals.

"The signal generated by the carbon nanotube device changed following the adsorption of specific single molecules," says first author Agung Setiadi. "This is because the adsorbed molecule generated a trap state in the carbon nanotube, which changed its conductance."

What this means is that the carbon nanotube-based devices were so sensitive that the researchers were able to detect unique signature from single molecules. The ability to characterize single molecules using highly sensitive nanoelectronics is an exciting prospect in the field of sensors, particularly for neuro- and biosensor applications.

"Use of noise signals to identify molecular activity ((interaction) or (active orbital)) is attractive for developing advanced sensing devices," explains corresponding author Megumi Akai-Kasaya. "We demonstrated that noise can be exploited to improve the signal detection ability of a device." The results of this successful demonstration will be published in the near future in a follow-up article.

Signal detection sensitivity may be increased through controllable noise generation. These carbon nanotube-based devices illustrate that it is possible to detect single molecules through their unique noise signatures in the device current signals. Improved knowledge of the molecular-level origin of noise should lead to the development of electronics that use noise to improve their performance rather than degrade it.

Facts, background information, dossiers

More about Osaka University

  • News

    Integrate Micro Chips for electronic Skin

    Researchers from Dresden and Osaka present the first fully integrated flexible electronics made of magnetic sensors and organic circuits which opens the path towards the development of electronic skin. Human skin is a fascinating and multifunctional organ with unique properties originating ... more

    Creative use of noise brings bio-inspired electronic improvement

    In conventional electronics, a great deal of effort is devoted to eliminating stochastic resonance (SR) -- the annoying hiss that generally hinders the detection of weak signals and degrades overall device performance. But, what if there were a way to exploit this effect to enhance signal t ... more

    How different drugs interact with the same target

    Tumor necrosis factor (TNF) is involved in a range of inflammatory diseases including rheumatoid and psoriatic arthritis, ankylosing spondylitis, and psoriasis. Several drugs that target TNF are available to treat these conditions; however, despite acting on the same target, their clinical ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by: