(July 10, 2015) Researchers
at EPFL and ICFO have developed a sensor made from graphene to detect molecules
such as proteins and drugs. This is one of the first devices exploiting the
unique electronic and optical properties of graphene for a practical
application. The work is published in Science.
Many areas of fundamental research are interested in
graphene owing to its exceptional characteristics. It is made of one layer of
carbon atoms, which makes it light and sturdy, and it is an excellent thermal
and electrical conductor. Despite its apparently limitless potential, however,
few applications have been demonstrated to date. Scientists at EPFL’s
Bionanophotonic Systems Laboratory (BIOS) together with researchers from the
Institute of Photonic Sciences (ICFO, Spain) have now added another one. They
have harnessed graphene’s unique optical and electronic properties to develop a
reconfigurable highly sensitive molecule sensor. The results are described in
an article appearing in the latest edition of the journal Science.
Focussing light to improve sensing
The researchers used graphene to improve on a well-‐known
molecule-‐detection method: infrared absorption spectroscopy. In
the standard method, light is used to excite the molecules, which vibrate
differently depending on their nature. It can be compared to a guitar string,
which makes different sounds depending on its length. By virtue of this
vibration, the molecules reveal their presence and even their identity. This
“signature” can be “read” in the reflected light.