Nav: Home

New sensor material could enable more sensitive readings of biological signals

October 07, 2016

Scientists have created a material that could make reading biological signals, from heartbeats to brainwaves, much more sensitive.

Organic electrochemical transistors (OECTs) are designed to measure signals created by electrical impulses in the body, such as heartbeats or brainwaves. However, they are currently only able to measure certain signals.

Now researchers led by a team from Imperial College London have created a material that measures signals in a different way to traditional OECTs that they believe could be used in complementary circuits, paving the way for new biological sensor technologies.

Semiconducting materials can conduct electronic signals, carried by either electrons or their positively charged counterparts, called holes. Holes in this sense are the absence of electrons - the spaces within atoms that can be filled by them.

Electrons can be passed between atoms but so can holes. Materials that use primarily hole-driven transport are called 'p-type' materials, and those that use primarily electron-driven transport are called, and 'n-type' materials.

An 'ambipolar' material is the combination of both types, allowing the transport of holes and electrons within the same material, leading to potentially more sensitive devices. However, it has not previously been possible to create ambipolar materials that work in the body.

The current most sensitive OECTs use a material where only holes are transported. Electron transport in these devices however has not been possible, since n-type materials readily break down in water-based environments like the human body.

But in research published today in Nature Communications, the team have demonstrated the first ambipolar OECT that can conduct electrons as well as holes with high stability in water-based solutions.

The team overcame the seemingly inherent instability of n-type materials in water by designing new structures that prevent electrons from engaging in side-reactions, which would otherwise degrade the device.

These new devices can detect positively charged sodium and potassium ions, important for neuron activities in the body, particularly in the brain. In the future, the team hope to be able to create materials tuned to detect particular ions, allowing ion-specific signals to be detected.

Lead author Alexander Giovannitti, a PhD student under the supervision of Professor Iain McCulloch, from the Department of Chemistry and Centre for Plastic Electronics at Imperial said: "Proving that an n-type organic electrochemical transistor can operate in water paves the way for new sensor electronics with improved sensitivity.

"It will also allow new applications, particularly in the sensing of biologically important positive ions, which are not feasible with current devices. For example, these materials might be able to detect abnormalities in sodium and potassium ion concentrations in the brain, responsible for neuron diseases such as epilepsy."
-end-


Imperial College London

Related Electrons Articles:

Cooling nanotube resonators with electrons
In a study in Nature Physics, ICFO researchers report on a technique that uses electron transport to cool a nanomechanical resonator near the quantum regime.
New method for detecting quantum states of electrons
Researchers in the Quantum Dynamics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) devised a new method -- called image charge detection -- to detect electrons' transitions to quantum states.
Slow electrons to combat cancer
Slow electons can be used to destroy cancer cells - but how exactly this happens has not been well understood.
How light steers electrons in metals
Researchers in the Department of Physics of ETH Zurich have measured how electrons in so-called transition metals get redistributed within a fraction of an optical oscillation cycle.
Twisting whirlpools of electrons
Using a novel approach, EPFL physicists have been able to create ultrafast electron vortex beams, with significant implications for fundamental physics, quantum computing, future data-storage and even certain medical treatments.
Inner electrons behave differently in aromatic hydrocarbons
In an international research collaboration between Tsinghua University in Beijing and Sorbonne University in Paris, scientists found that four hydrocarbon molecules, known for their internal ring structure, have a lower threshold for the release of excess energy than molecules without a similar ring structure, because one of their electrons decays from a higher to a lower energy level, a phenomenon called the Auger effect.
Exotic spiraling electrons discovered by physicists
Rutgers and other physicists have discovered an exotic form of electrons that spin like planets and could lead to advances in lighting, solar cells, lasers and electronic displays.
Racing electrons under control
The advantage is that electromagnetic light waves oscillate at petaherz frequency.
Electrons go with the flow
You turn on a switch and the light switches on because electricity 'flows'.
Tying down electrons with nanoribbons
Nanoribbons are promising topological materials displaying novel electronic properties. UC Berkeley chemists and physicists have found a way to join two different types of nanoribbon to create a topological insulator that confines single electrons to the junction between them.
More Electrons News and Electrons Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.