Flaky graphene makes reliable chemical sensors

Jan 17, 2012

Scientists from the University of Illinois at Urbana-Champaign and the company Dioxide Materials have demonstrated that randomly stacked graphene flakes can make an effective chemical sensor.

The researchers created the one-atom-thick carbon lattice flakes by placing bulk graphite in a solution and bombarding it with that broke off thin sheets. The researchers then filtered the solution to produce a graphene film, composed of a haphazard arrangement of stacked flakes, that they used as the top layer of a chemical sensor. When the graphene was exposed to test chemicals that altered the surface chemistry of the film, the subsequent movement of electrons through the film produced an electrical signal that flagged the presence of the chemical.

The researchers experimented by adjusting the volume of the filtered solution to make thicker or thinner films. They found that thin films of randomly stacked graphene could more reliably detect trace amounts of test chemicals than previously designed sensors made from carbon nanotubes or graphene crystals.

The results are accepted for publication in the AIP's journal .

The researchers theorize that the improved sensitivity is due to the fact that defects in the carbon-lattice structure near the edge of the graphene flakes allow electrons to easily "hop" through the film.

Explore further: Graphene surfaces on photonic racetracks

More information: Amin Salehi-Khojin et al. "Chemical Sensors Based On Randomly Stacked Graphene Flakes", accepted for publication in Applied Physics Letters.

add to favorites email to friend print save as pdf

Related Stories

Liquid method: pure graphene production

May 30, 2010

In a development that could lead to novel carbon composites and touch-screen displays, researchers from Rice University and the Technion-Israel Institute of Technology today unveiled a new method for producing ...

Giant flakes make graphene oxide gel

Oct 20, 2011

(PhysOrg.com) -- Giant flakes of graphene oxide in water aggregate like a stack of pancakes, but infinitely thinner, and in the process gain characteristics that materials scientists may find delicious.

Recommended for you

Graphene surfaces on photonic racetracks

10 hours ago

In an article published in Optics Express, scientists from The University of Manchester describe how graphene can be wrapped around a silicon wire, or waveguide, and modify the transmission of light through it.

Simulating the invisible

11 hours ago

Panagiotis Grammatikopoulos in the OIST Nanoparticles by Design Unit simulates the interactions of particles that are too small to see, and too complicated to visualize. In order to study the particles' behavior, he uses ...

Building 'invisible' materials with light

12 hours ago

A new method of building materials using light, developed by researchers at the University of Cambridge, could one day enable technologies that are often considered the realm of science fiction, such as invisibility ...

User comments : 0