Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Graphene imperfections key to creating hypersensitive 'electronic nose'

23.09.2014

Researchers have discovered a way to create a highly sensitive chemical sensor based on the crystalline flaws in graphene sheets. The imperfections have unique electronic properties that the researchers were able to exploit to increase sensitivity to absorbed gas molecules by 300 times. The study is available online in advance of print in Nature Communications.

Amin Salehi- Khojin, asst professor of mechanical and industrial engineering in the lab with Mohammad Asadi, graduate student and Bijandra Kumar, post doc where they are doing research in graphene sensors. Photo: Roberta Dupuis-Devlin/UIC Photo Services

When a graphene lattice or sheet is formed, its polycrystalline structure has random boundaries between the single-crystal grains. The properties of the lattice are significantly affected by these "grain boundaries," said Amin Salehi-Khojin, UIC assistant professor of mechanical and industrial engineering and principal investigator on the study.

In many applications, grain boundaries are considered faults because they scatter electrons and may weaken the lattice. But Salehi-Khojin and his colleagues showed that these imperfections are important to the working of graphene-based gas sensors. They created a micron-sized, individual graphene grain boundary in order to probe its electronic properties and study its role in gas sensing.

Their first discovery was that gas molecules are attracted to the grain boundary and accumulate there, rather than on the graphene crystal, making it the ideal spot for sensing gas molecules. A grain boundary's electrical properties attract molecules to its surface.

A theoretical chemistry group at UIC, led by Petr Kral, was able to explain this attraction and additional electronic properties of the grain boundary. The irregular nature of the grain boundary produces hundreds of electron-transport gaps with different sensitivities.

"It's as though we have multiple switches in parallel," said graduate student Poya Yasaei, first author on the paper. "Gas molecules accumulate on the grain boundary; there is a charge transfer; and, because these channels are all paralleled together, all the channels abruptly open or close. We see a very sharp response."

Researchers have been trying to develop a highly sensitive and robust sensor for decades, said UIC postdoctoral fellow Bijandra Kumar, a co-author on the paper.

"We can synthesize these grain boundaries on a micrometer scale in a controlled way," Kumar said. "We can easily fabricate chip-scale sensor arrays using these grain boundaries for real-world use."

Salehi-Khojin said it should be possible to "tune" the electronic properties of graphene grain-boundary arrays using controlled doping to obtain a fingerprint response -- thus creating a reliable and stable "electronic nose."

With the grain boundary's strong attraction for gas molecules and the extraordinarily sharp response to any charge transfer, such an electronic nose might be able to detect even a single gas molecule, Salehi-Khojin believes, and would make an ideal sensor.

###

Other co-authors are Reza Hantehzadeh, Artem Baskin, Nikita Repnin, Canhui Wang and Robert Klie of UIC and Morteza Kayyalha and Yong Chen of Purdue University.

This work was supported by a UIC Startup budget; National Science Foundation DMR Grant No. 1309765; the acquisition of the UIC JEOL JEM-ARM200CF is supported by a MRI-R2 NSF grant, DMR-0959470; resources of the National Energy Research Scientific Computing Center, supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, and the Extreme Science and Engineering Discovery Environment (XSEDE), supported by the NSF Grant No. OCI-1053575; and partial support from the U.S. Defense Threat Reduction Agency.

Jeanne Galatzer-Levy | Eurek Alert!
Further information:
http://www.uic.edu

More articles from Life Sciences:

nachricht Blood test shows promise for early detection of severe lung-transplant rejection
23.01.2019 | NIH/National Heart, Lung and Blood Institute

nachricht Evolution of signaling molecules opens door to new sepsis therapy approaches
23.01.2019 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Bifacial Stem Cells Produce Wood and Bast

Heidelberg researchers study one of the most important growth processes on Earth

So-called bifacial stem cells are responsible for one of the most critical growth processes on Earth – the formation of wood.

Im Focus: Energizing the immune system to eat cancer

Abramson Cancer Center study identifies method of priming macrophages to boost anti-tumor response

Immune cells called macrophages are supposed to serve and protect, but cancer has found ways to put them to sleep. Now researchers at the Abramson Cancer...

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...

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

A New Home for Optical Solitons

23.01.2019 | Physics and Astronomy

Graphene and related materials safety: human health and the environment

23.01.2019 | Materials Sciences

Blood test shows promise for early detection of severe lung-transplant rejection

23.01.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>